I bought an 04 for my 16 year old son's birthday in April and ran into the same thing. Took it to the independent mechanic I use in Houston that has serviced my SL and S class MB. He said he couldn't service it. I showed him that is was the same as a 1st generation SLK, and when he popped the hood he just smiled and said, "this has all MB parts." I said, yeah, that's what I've been telling you. He hooked it up to the computer and it gave him an immediate read out of all diagnostics. He then said he could easily service it for me without a problem. It made me feel much better, because he has serviced my cars for over 20 years and I trust him. He just had to be educated that it really is a little MB on the inside. One note, if you hook it up to the computer as an 04 SLK it won't read it, but if they set the diagnostics for a first generation SLK (like maybe an 01) it immediately reads all the diagnostic codes. Good luck.