Just happened upon this thread and would like to offer my suggestion, I had a local company install this finish in my garage:
http://www.parkplacegarage.net/garage-flooring.html
Apparently it is called: polyaspartic polyurea garage flooring
I am not sure of the construction but the stuff looks unbelievable and is exactly as advertised. Its tough and does not leave tire marks from hot tires. Super easy to clean as well and does not stain.
