Last fall had an oil change done, oil filter was not installed correctly. After several days of driving the serpentine belt slipped off due to oil accumulation, I was 2 blocks from home when it happened, lost power steering but engine did not overheat. I had it towed to a local certified MB repair shop, they put on a new belt and power washed the engine bay.

A month later the inside of the windows had frosted, sure enough, the drivers side carpet was soaking wet. I dried it out and no more problems the few times I drove it before winter hibernation.

I drove the car a couple times each in January and February when the roads were clear, then started driving it more regularly earlier this month. No wet carpets until today. Again, this morning the inside of the windows were frosted and the drivers side carpet was soaking wet.

My first thought last fall was when it was power washed maybe water leaked into the passenger compartment, but that would not explain the wet carpet now. Is the heater core in need of repair? Please don't tell me it blew a head gasket, the engine is running fine at normal temps. I'll take the car back to the MB garage, but would like to go in with a little knowledge ahead of time.