Ha ha! I've been playing my Forza Motorsport 3 Limited Collector's Edition ever since the midnight release and had been lovin' it! I hope they add the smart in on the DLC car/track pack this December.
My favorite cars so far are:
Lamborghini Reventon
Lamborghini Murcielago LP640
Fiat 500 Abarth essesse
Bugatti Veyron 16.4
2009 Corvette C6 ZR1
2006 Dodge Ram SRT10 (Viper engine!)
Saleen Supercab F-150
Porsche Cayenne Turbo (my drift car)
Chevrolet Aveo5 LT (S class baby! 186mph top speed!)
Creepiest car so far:
Ford GT (look at the speedometer...

...)
Fastest ever driven:
248mph (Bugatti Veyron stock tuned).
Most rolls in a crash:
6 (2008 Porsche 911 GT2)
If you're disappointed about no smarts in Forza, I did happen to install a 450 on my Grand Theft Auto: San Andreas for the PC.