I guess this is common knowledge among some VW owners but the RainX washer fluid creates problems with VW's and Audi's. I found that out the hard way. After buying Rain X 2 in 1 fluid and filling our Tiguan's reservoir up for a trip my wife took, she came back with the warning light on to refill the :banghead:washer tank. It wasn't empty but I topped it up and the light would still not go out. Asked my VW dealer to look at it today when they changed my tires. They informed me there was a problem with the RainX formula and it has a high salt content that clogs the sensors and can ruin them. Bottom line, it's an hour of labor for them to drain the tank, clean the sensor, and refill with proper fluid. I'm going to contact RainX to see if they will cover any of this cost but it's an expensive lesson.