Anyone hear of any problems with windshields cracking? I have a 2001 SLK320 which has developed a crack on the passenger side windshield, about a foot long and an inch up from the bottom. I don't recall an impact plus the crack is actually behind the wiper blade which would seem to make impossible for something to have hit it with doing some kind of damage to the wiper arm (and there is none)...

Thanks for any input!