Greetings!
I have a 2008 A6 4.2L Quattro. About 6 months ago the "rear right reversing light," the "rear right fog light," and "rear right light" warning started coming on intermittently. I checked all the lights and all of them were working. Then the warnings would not come on for a while. Then I noticed that the warnings were coming on when I drove in the rain (here in Central Florida that's almost a daily routine!). After a couple days without rain the warnings stopped coming on. Today I washed the car, then drove to the store. The warnings came on again. This is terribly annoying, especially since the lights are all working. Anyone know why this is happening? And is it something I can fix?

Thanks!

 

Most likely water is entering into the right rear light housing which is causing a short or a change in resistance making the module think that there is an issue with those lights.

Pull the housing off and examine the interior for moisture, as well as the back part that is actually in the car/trunk area.