for me:
mid-front N/A <12000RPM redline 6.0L W-24
4WD with VCD adjustable from 50/50 to 100% RWD
7-spd SMG
ceramic brakes
carbon fiber whatever...blah blah
all wrapped in a sleek curvy long-bonnet body (think Carrera GT with SLR proportions...or a modernized 275GTB)
oh, and an all suede interior with carbonfiber trim (think CSL)