Try this post in wheels and tires section.
go to
www.tirerack.com and read reviews.
Post what kind of mercedes, year, model, wheel size, color, interior color, miles, modifications, and pics if you got em, we like to know these things.
You should post about your driving style as well, it helps when choosing tires.
Mileage requirements?
Noise requirements?
Ride requirements?
Size?
Allt hsi will definately help you get a good answer.
Also try searching, it should turn up a few reviews/recommendations.
Alon