Two repairs: 1) Noticed a coolant leak and traced it to the coolant tank. The small hose barb that the small hose connects to on top had cracked. I've seen where some owners have replaced this hose barb with a brass one from a hardware store, but I just bought a replacement tank. I saw some online for about $70 with free shipping, but I was in a hurry because I didn't want the problem to leave my wife stranded somewhere. I bought one from the Chrysler dealership for $90 (Mercedes had one for $114). Swapping the part out was pretty easy but I spilled more coolant than I intended to. 2) Cleaned our MAF sensor. We had been dealing with an intermittent and worsening rough idle and sometimes when giving it gas from a standstill at a light, the engine would stumble as if it was about to die. I had reset the accelerator pedal a few times, and checked the air filters, but I thought I'd give the MAF sensor clean a try. I followed a couple different pictorials on some MB forums. One was particularly helpful ( http://www.benzworld.org/forums/atta...eaning-maf.pdf) because it showed exactly where to clean the sensor. My sensor did not appear to be dirty when I took it apart. It may be too early to tell if this is the fix, but I noticed an obvious improvement in throttle response, so I'm hopeful.