I bought mine at a dealer that is "Crossfire Certified" this means that they maintain a Crossfifre certified tech on staff at all times. The MB dealer does not. I went there just to ask if they service them, and they directed me to the dealer where I bought the car. They said that just because it shares some SLK parts, the car is uniqe. They did say that they could do regular maintenance, changing the oil, etc. So find a certified dealer, and go there exclusively!
The top operating intermittently sounds like the prople I have once in a while. I have a bad sensor on the trunk panel. This is a warranty issue, and I beleive the sensor was recalled (I was told this, but I have not verified it, it may just be a TSB). The top (once in a while) will not go down, but once down will always go up. Once it went down, but the panel was not in position. There are 2 sensors, one on each side where the panel snaps in place.
Starting on page 195 of the owners manual is a description of how to manually lower the top.
COOL! I will look in the manual tonight on putting it down manually. I do not have the tool, but I am sure that I can come up with something that will work
