Merc CL65 (S4E7) I think... JC complained that it was so ridiculously powerful, yet still looked the same as a regular Merc, so you'd - literally - have to advertise the fact that your car is better for anyone to notice.
"It's a supercar, it doesn't have vertical takeoff"
I have not seen this one for a long time, surely it can't be forgotten!?
http://img18.imageshack.**/img18/6243/jeremyapprove.png