I purchased my 98 Golf from a dealer and have no idea what the stereo code is. So will I be hosed if I have to disconnect the battery? Will not having the code give me any problems when I go to install a new head unit? Also while we're talkin about stereos...does anyone make an internally mounted antennae? I want to ditch the fender mount one but I'm thinkin that putting on a roof mount is gonna suck. Does it? Would be slick to have nothing on the outside of the car. Thanks.