How about shuffle races? Those could be fun. Random cars with similar specs, and it shuffles everytime the track changes. 
(and not that those are absolute requirements, just an example)

She's a fun one!






I ran it down quite a bit the past few days without rebuilding / oil changes, went down to about 866bhp before the oil warning light finally went on.




I love those nippy little vintage racers, they look like so much fun.