Project Turbunnium Part II: Body Modifications

I first met the Thunder BunnyTM in a dimly lit corner of a display hall at Chicago’s McCormick Place in 2007. Designed and built at Volkswagen’s Design Center California in Santa Monica, the Thunder Bunny paid homage to the Neuspeed-modified 1981 Rabbit of the same name that foreshadowed the arrival of the 1983 GTI. The Thunder Bunny, with its Candy White paint and pearlescent-swirl accents, was also the driving force behind purchasing our Candy White 2007 Rabbit. When we bought the car, rumors had come to us via Auburn Hills that the Thunder Bunny’s body kit was going to see production, and the thought of building a car patterned after VW’s show beauty was irresistible. Two months ago, the first prototype body kits began filtering out of VW, and we were able to snap one up.

The Con-Way delivery truck hadn’t even pulled away from the Vortex offices before we were elbows-deep in three large cardboard boxes. The body kit features three components — a front bumper, a rear bumper, and side skirts — which are available pre-installed on new GTIs and Rabbits, or a la carte in either primered or prepainted form for non-foglight (Rabbit and Jetta) or foglight (GTI and GLI) applications. We opted to have the bumpers and skirts prepainted in Candy White for our Rabbit to make installation easier. Like the Thunder Bunny, we chose to go with a black grille, although Rabbit owners can retain their original body-colored piece if the monochromatic look is preferred.

Installing the pieces doesn’t take more than a day’s worth of work, a few friends, and some hand tools. We’ve worked up a broad overview of the process to give you an idea what you’re in for if you want to try your hand at upgrading your VW by yourself.

Front bumper:

• Remove the two screws holding the grille to the body. Release the two locktabs holding the grille in place and it will tilt forward and pull off in your hands.

• With the grille removed, take out the screws holding the bumper to the radiator support, the screws holding the bumper to the fender and the wheel well liner, and the screws holding the bumper to the underside of the body. You may want to turn the wheels hard to each side to give yourself extra access to them.

• Enlist the help of a friend to pull the bumper straight forward and off of the car. There are two locking tabs that need to be released on the inside of the lower grille before the bumper can be removed. There will be wiring looms for the front marker lights that you’ll want to remove, so unplug the connectors from the side marker lamps and gently tug on the plastic Christmas-tree clips attaching the wiring harness to the front bumper. Set these aside, as you’ll need to reuse them. Remove the side markers by pressing down on their locking tabs and pressing them through the sides of the bumper.

• With the bumper removed and set aside, you’ll need to remove the old reinforcing foam pad from the steel bumper bar. There is a new pad included with the Thunder Bunny bumper.

• The shape of the Thunder Bunny bumper necessitates removing some of the support bracket under the headlights. We used an angle grinder to make short work of it, but you can easily use a pliers to snap off the pieces that need to go — here’s a “before and after” to give you an idea of what needs to be lopped off.

• Now you’ll need to assemble the Thunder Bunny front bumper. There are three lower grilles that need to be installed, two blackout covers that go behind them, a mounting bracket that the grille attaches to, two guides that direct air through the radiator that need to be attached on either side of the lower valence, and two filler plates that extend out to attach the sides of the bumper to the wheel well liners, because the Thunder Bunny bumper is almost 2″ wider at its base than the stocker. Installing the center grille is a simple matter of lining up the mounting tabs, making sure the piece is seated fully, and pressing down supplied one-time use clips over the tabs to lock it in place. The side grilles require inserting gray plastic expansion plugs into holes in the bumper. Be sure to insert them so the slot in the plug is parallel to the slot in the bumper as pictured. With the plugs in place, install the mesh grilles and fasten them down using the supplied Phillips screws. After the grilles are in, you can install the rear covers by locating them over the mounting tabs on the rear of the bumper and securing them in place with one-time use clips. The upper bracket and lower air guides are held in place by four Torx scews and four pop rivets, which are supplied, and are tightened down by using a pop-rivet gun, which isn’t. New ones are under $12 at Autozone, however. The filler plates for the bumper sides are held in place by Torx screws, which are also included in the bag of hardware.

• The bumper is almost ready to install at this point — there’s just one more step to assemble the front bumper before putting it on the Rabbit. The lower spoiler is made out of an extremely firm rubber and snaps into slots alongside the bottom of the front bumper. Start at one end of the bumper and you’ll be able to easily snap the strip into place.

• Remove the backing from the tape strips on the new bumper foam and install it.

• You’ll need to snap in your old turn signals or (as you should!) new smoked turn signals. Carefully route the wiring loom from the front of the car so that it won’t get pinched or hung up on any of the brackets.

• With someone on each side of the car, carefully guide the mounting tabs into the slots on each side of the fender. Make sure that the wiring for the turn signals doesn’t got caught on the bumper bar as you slide the bumper into place. Install the screws into the grille bracket and wheel well liners.

• The Thunder Bunny bumper sits nearly an inch lower than the stock bumper, so there are spacers and longer screws supplied to hold the new bumper to the original mounting locations. Make sure that you use the correct spacers and screws in the correct locations — the included instructions show exactly where they should go.

• Snap in the towing eyelet cover and install the new grille. The VW emblem snaps into place with a clockwise turn.

Rear bumper:

• Open the hatch and, using your fingers, locate the two slits in the trunk carpet that allow access to the nuts holding in the taillights. If you haven’t yet removed your taillights, there will be small perforations holding the carpet together that you’ll need to tear.

• Using a small flatblade screwdriver, release the tabs that hold the wiring harness to the taillights by turning the blade until the catch releases.

• Remove the two 10mm nuts that are holding the taillights against the body and gently remove them. It’s very easy to accidentally scratch the paint when pushing the threaded studs out, so be careful.

• With the taillights removed, you’ll have access to the four screws holding the bumper to the car’s body. Those need to be removed, as well as the screws holding the bumper to the wheel well liner (there is one vertical screw on each side that is difficult to get to — removing the wheel allows much better access to them) and the screws on the underside of the bumper that hold it to the underbody.

• With the screws removed, the bumper simply slides off the car. Be sure to unplug the two license plate lights and carefully remove the clips that hold their wiring loom to the bumper.

• Unlike the front bumper, there isn’t much assembly work that needs to be done before installing the rear bumper. There are spacers on each side that need to be attached using Torx screws, but other than that the bumper is ready to install as it’s shipped.

• If you ordered the bumper prepainted, the lower valence will be body color. We decided that we wanted ours to be semi-flat black to match the rub strips on the Rabbit, so we scuffed it down with 3M pads, washed the area with Eastwood pre-paint prep solvent to remove any oils and dust, primed the area, and sprayed it with flexible bumper-and-trim paint. If you’re doing this yourself, it’s vitally important to make sure that the paint you use is designed for use on bumpers and plastic parts. Most paint does not have a flex agent mixed in with it and will chip, crack, craze, and flake off after a short while. Even if nobody bumps your car, the expansion and contraction of plastic bumpers sitting in the sun can cause the wrong paint to crack!

• While the paint is drying, take this opportunity to remove the old reinforcing foam bar and install the new one that came with the Thunder Bunny rear bumper. The different shape of the bumper cover necessitates the new foam bar to keep it from being loose.

• Remove the license plate lights from the old rear bumper, noting the direction that they were mounted. The lights have reflectors in them to shine light on the rear plate, and if they’re installed backwards they won’t light up much of anything. The two lights pop out easily by pressing in their locktab and pushing them out, much like the front sidemarkers.

• Install the lights into the new rear bumper in the reverse of how you removed them from the old bumper.

• Installing the new bumper is a simple matter of sliding the side mounting tabs into place and reinstalling the screws that were originally removed. Before sliding the bumper fully into place, reconnect the rear license plate lamps and clip the wiring loom to the new bumper using the original push-on mounting clips.

• The lower valence of the Thunder Bunny bumper is slightly longer than that of the stock bumper, which gives the stock exhaust tips a slight (half-inch) recess. We plan on upgrading the exhaust system of our Rabbit in a future installment, but if you’re staying stock, you may want to invest in a set of longer tips.

• There are no holes drilled for the license plate frame, so — heartbreak! — you’ll need to take a drill to the freshly-painted surface of your new rear bumper. We held the plate up to the surface, made sure it was centered, traced the holes with a pencil, and drilled four 1/8″ pilot holes. The screws for the license plate are self-tapping, and we let them cut threads into the cover.

Side skirts:

Note: Installing the side skirts requires permanently bonding them to the sides of your car using windshield adhesive. Following the procedure to the letter is required, so if you’re not confident in your ability to run an even bead of urethane along the sides of the skirts or don’t feel comfortable with irreversibly modifying your car, you may want to have a body shop install them for you.

• On the underside of your Rabbit’s rocker panels, there will be several rubber body plugs. These will be removed and the holes in the body will be used to attach the side skirts’ mounting brackets. Hold the skirt up to the car to determine which plugs need to be removed and yank them out with a gentle tug.

• Insert the mounting brackets for the side skirts by pushing them into the holes — there will a soft “snap” as they go into place — and then push the plastic box in the middle of the mounting bracket flush with the body of the bracket. This is a locking tab that prevents the bracket from ever falling off of the car.

• Remove the Torx screws at the bottom of the front and rear wheel well liner, and the lone screws at the rear side that holds the liner to the bottom of the rocker panel. You’ll need to reuse these later on to attach the side skirts.

• Using sandpaper or a 3M scuff pad, rough up the flat area of the side skirt where you’ll run the bead of urethane adhesive. Use a good prep solvent, like the Eastwood pre-paint prep we used on the rear bumper, to make sure that the area is free from dust, dirt, and skin oils.

• Wipe down the lower half of the car’s body and rocker panel using prep solvent to remove any wax or contaminants. We went over the body with a clay bar beforehand to remove any impurities in the paint, then wiped it down with prep solvent for good measure. The urethane will be bonding directly to the paint itself, so this step is critical.

• Attach the side skirts to the car using the two mounting blocks you inserted into the rocker panels earlier. The skirts have some lateral adjustment built into these holes, so you can slide them forward and back to line them up on the body.

• To help make cleanup easier, we first held the skirt to the body and laid down blue masking tape along the side of the body. We then traced the outline of the skirt on the tape with a pencil, and carefully scored the surface of the tape with a razor blade, removing any tape that would land under the area of the side skirt. This way, if any urethane were to ooze out during installation, it would stick to the tape and could be easily removed later, instead of having to deal with the urethane smeared on the body.

• Securing the proper urethane in important! The included instructions call for Dow BETASEAL urethane, which is used to adhere glass directly to the body, such as the rear hatch window and side windows of the MKV. The only places that carried Dow BETASEAL were glass-repair shops, which sold it in 50-gallon drums. An equivalent product is 3M 08693, which is available at most NAPA auto parts stores. A note of caution — the windshield urethane that’s sold at most chain parts stores is 3M 08609, which is a different adhesive and doesn’t meet the standards laid down for the skirt adhesion.

• Using a household caulk gun, apply a ¼ to 3/8″ bead of urethane along the flat surface on the edge of the side skirt, making sure not to squeeze excess onto the surface of the side skirts.

• Take a deep breath and position the skirt on the side of the car, taking care not to move it up or down too much so that the urethane doesn’t poke out above the surface of the skirt. We installed the front screw to retain the skirt while leaving the bottom two screws loose and the rear screws uninstalled so that they weren’t trying to pull the skirt away from the body.

• Using gaffer tape (duct tape will work here as well, but will leave more adhesive behind), run long stretches of tape to affix the skirt to the car body while the urethane cures. Use three stretches along the door sills and one long stretch to hold the skirt below the front fender. We used masking tape instead of gaffer tape (available from your local A/V store or Guitar Center) and encountered problems with the pieces sagging during the curing process, necessitating ripping them off the body, scraping the old urethane with razor blades, and trying again. To keep the long, upright section in front of the wheel attached, we used two ratcheting tie-down straps looped together to encircle the car, with rolled-up bunches of cardboard underneath the strap to keep the skirt pressed firmly against the Rabbit’s body surface. Small C-clamps, designed for woodworking, held the skirt against the wheel well firmly.

• After waiting the longest 24 hours of our lives, we removed the tape, cleaned up any adhesive residue, and tightened the two screws on the mounting blocks and the front screws holding the skirt to the fender well. The remaining screws on the rear of the skirt were then installed and snugged down. In our case, the skirt required a bit of coaxing to make it fit properly, as the stone-chip coating that’s sprayed inside the rocker panel prevented the skirt from sitting tight against the body.

All told, we were able to do the entire job without the need for power tools or even much in the way of hand tools. The kit from Volkswagen comes with everything you’ll need to do the installation — every screw, bracket, zip tie, and piece of tape has been included — so there were none of those awful job-stopper moments that required waiting a week for the dealer to order a part of overnighting some obscure fastener bit from Germany.

The fit and finish of the Thunder Bunny bumper is just as good as original equipment, which is exactly what we’d wanted — when removing factory parts, we wanted to replace them with things that would also look and feel like something that could have come down the assembly line. It’s worth noting that the Thunder Bunny parts are durable enough to see use on every one of the TDI Cup racers that Volkswagen is currently campaigning.

We love the look of the Thunder Bunny kit — the prominent black grilles complement the black rub strips along the car’s flanks and the blacked-out rear diffuser adds some much-needed aggression to the Rabbit’s formerly homey heinie. There’s a problem, though: With the body kit in place, we need to do something to cure our Rabbit’s family-friendly ride height and thick sidewalls. Stay tuned for the next installment of Project Turbunnium, where we’ll give our VW’s suspension and rolling stock some much needed love. Until then, be sure to drop by the VWvortex booth at Waterfest this coming weekend and see Project Turbunnium, sporting its full body kit, for yourself.


Thunder Bunny Body Kit – Primered:

JNV807101D Front bumper, Rabbit 2.5 without fog lights

JNV807301D Rear bumper, Rabbit 2.5

JNV807101E Front bumper, GTI/GLI 2.0T with fog lights (includes prepainted in black magic grille and VW emblem)

JNV807301E Rear bumper, GTI

JNV853751 Side skirt set, 2 door

JNV853751A Side skirt set, 4 door


Volkswagen DriverGear

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