I'm looking for someone, not wanting to go to the dealer, who specializes in Mercedes.

Any suggestions?

Thanks

Wherever you go, cost will be significant especially if parts need to be replaced.

Try Benz T.B.V. Auto Service (opposite Phuket Villa 3) since you don't wish to deal with Phuket Benz, they are bit cheaper:

http://phuketdir.com/benzservice/index.htm

There is also a shop that works on BMW's and Mercedes on the road out of Phuket Town just before you turn left to go to Cape Panwa. 

Thanks for the leads gents. I had a lot of work done at the shop that does all the high end cars near to Immigration in Phuket town, but feel I've been ripped off, and need some more work done. I'll report back with results.

Cheers

I've also had work done on my old German car next to ptt gas station going from Phuket Town towards Chalong.  There's a small soi right before the gas station and you drive about 100 meters back and the garage is directly behind the gas station.