Ferrari FXX (2005–2007)
Customer track special powered by 6,262 cc V12 engine that can punch out over 800 hp at 8,500 rpm. Its gearbox is the result of the transfer of F1 strategies, delivering gear change times of under 100 msec.
This is almost as fast as the F1 single-seaters, themselves: was the 2008 pinnacle of technological achievement. Sophisticated telemetry, etc.
Dedicated track events so the super rich can share their driving or show off to a passenger.