About drag limit. It is a little bit strange to me. Here are few facts:
Audi TT mk2 (second generation):
Drag coefficient 0.30
2.0TFSI FWD S-line - 2889 lbs curb weight - 200HP
my top speed was 280+ km/h on tachymeter (272 km/h by Garmin GPS) on long straight on Autobahn with grippy tyres, but traction control since 260 was blinking
Tyres - 245/40/18" (in S-line, basic were 225/50/16")
3.2 VR6 quattro with 3250 lbs (3262 lbs for S-tronic) curb weight - 250HP
electronically limited top speed to 250 km/h
Tyres - standard 225/44/17"
TTRS 2012 MT - 3306 lbs - 360HP
Drag coefficient 0.32
Top speed electronically limited to 250 km/h or 280 km/h (option with Carbon Air Box). BTW: 0-62 in 4.1s in 2012 version!
Tyres - 245/40/18" - Height is 10mm lower than standard TT
370Z 3232 lbs curb weight - 328 HP (in Europe)
Drag coefficient 0.29 in sport package thanks to chin spoiler and rear wing
(0.30 in BASE)
Top speed 250 km/h - why not higher without el. limiter?