[MikeK]

Consider three SS sheet metal drip pans and four 1' square wheel pads that can easily be moved, cleaned, and placed when you take the car in and out. Cleaning the floor will be much easier!
Any large unglued roll flooring will tend to move, bunch and not lie flat when a car is rolled over it.

If you absolutely must, here's a place that sells heavy weight roll garage flooring: LINK