Mine would have to be the ENGINE - the 5.5 liter hand built V8 is a trophy of mechanical art. The Engine consistently proves it's ability to provide the driver with awesome power at low and high ends in both HP and torque. I sometimes wonder what my Boxster S would be like with the CLK 55 engine installed
Daily the V8 places a smile on my face, even at the gas station which I visit so often.

Favorite attribute = easy to make friends with the AMG

Gestalt synergism:

The whole is more than the sum of it's parts!

The 208 CLK55 AMG Coupe is the best car ever produced since Karl Benz
patented the world's first motorcar in 1886, registered his patent DRP
37435, which is considered as the official birth certificate of the first motor
car!

2 things:

1. the hand built v8 with an Authetic signature engraved by the mechanic who built the engine x 3450380

2. The missing B-pillar.. car looks insanely sick when all windows are rolled down.

Mine would be: Delivery of my Cabriolet.
It was supposed to be delivered on 09/23/03, but no one can seem to presently locate it.
The dealer assures me it is built or being built right now, but no VIN or location.
Seems odd to me. When I got my '02 M3, BMW seemed to know precisely where it was each day and it arrived exactly on schedule.
MBZ seems to have no clue about such things, so my excitement is turning into anxiety.