It would be cool if cars had specs to match with them. It would make for good boasting about your ride, and better help mechanics/street racers/ etc. I know these arent high demand right now, but it dosn't really require codeing until people are actually detailing their rides and raceing and such.
example:
2089 hondamitsu Mono
1.6 Single overhead cam 4 cyclinder engine making 105 hp and 110 lbs torque.
2089 Hondamitsu Duo
2.0 Dual overhead cam 4 cylinder engine making 175 hp and 150 lbs torque.
You don't really have to know much about cars to make up numbers and implement them way down the line. You could also add other tidbits like 1/4 mile times and shit too.
Sorry, I've been looking at too many sports cars lately.