John is right. If you want a long-lasting floor then the 2 part epoxy or urethane finishes intended for industrial use, are the only way to go. An awful lot of the home center floor paints will lift from hot tires. When a hot tire comes to rest on the paint, it reactivates the paint and makes it bond to the tire. When the car rolls out, it pulls the paint up. The main difference between epoxy and urethane finishes is in the gloss and abrasion resistance. The Epoxy has a lot more abrasion resistance, while the urethanes have a spectacular gloss. There are many shops which use epoxy for the base coat and then top coat with clear urethane for the gloss. Urethanes can be top coated in the future with little preparation while epoxies will need to be sanded for proper adhesion. We use Sherwin Williams epoxies and urethanes both on our shop floors at work, and we have been very pleased with the performance. It will cost about $600 to do a good sized 2 car garage floor if you do the work yourself, so the material is not cheap, but it will last!
Regards, John McGraw