The 55 AMG is THE car to have. I was looking at the BMW M3, but settled on the AMG for the torquey V8 and the sound that comes from the AMG exhaust.
This car is fast. It's stylish too. I have 18" AMG wheels on it with 225/40's in the front and 265/40's in the rear. If I turn off the skid control, I can get the back end out and the car going sideways with no problem. And that's with the bigger, wider tires!
Mustang, Trans-Am, Porsche, Lexus, Corvette, RX-7, 1000cc superbikes; I've driven or ridden them either on the street or at the race track.
I haven't taken this AMG to the track and I don't think I will, but I know it's pretty darn quick.
The maintenance is easy so far. I've done spark plugs (Iridium), engine oil, trans fluid, engine air filters, cabin air filters, & alternator VR repair.
The CLK55 comes with high performance AMG suspension, exhaust, hand-built motor (with the builder's nameplate attached) and brakes.
My car rides a little harsh because of the larger wheels and lower profile tires.
The seat feel like they wrap around you. Very sporty and comfortable at the same time.