If you go to the Mopar Nats the second week of August, they have racing there at the track.
Then Detroit is about 4 hours north of there and the Woodward Dream Cruise is the next weekend, but they start cruising all week long.
The Dream Cruise is an experience in itself as it's more "interactive". You can cruise up and down Woodward, or park on a side street somewhere and walk or sit along Woodward and watch all the cars go by.
The city buses are free up and down Woodward all day if you need to ride the bus.
If you do the Nat's - Dream Cruise, you can experience the different types of cruising all in a week and a half...