One problem related to wiper has been reported for the 2012 Mercedes Benz GLK350. The most recently reported issues are listed below.
I was driving with my heat on in cold weather. I was in motion when I heard a loud pop. I was on route 1 traveling straight on the road. At first I thought it was my windshield. Then I heard a crackling sound above me. The whole front panel sunroof now looked like crackle glass. When I got home I looked to see if something had hit the sunroof but nothing had. When I contacted my merecedes dealership they would not acknowledge there was a problem even though I had told them what the mercedes blogs were saying. I had the dealership replace the sunroof. The panel cost $1131. 20 plus labor $402. 50.