Not enough, I can't choose only 7 cars... :P
New fun passtime for ya. Buy a **** ton of ammo (ideally a sniper rifle) and the thickest body armor. Go climb into a train, kill the conductor (I'm not sure if this is a requirement or not) and then just start shooting at cars. The train goes all the way around the map and the cops cant get to you. They send choppers but you have plenty of warning and time to work on your accuracy with the sniper as they catch up.
I got 6 stars and then the train went into the city and I lost the cops, without even gettin off the train. Your welcome.
