Can you recommend a cleaner for the tiles. Also, I have tire marks (brownish color) on the gray tiles that I can't get out. Any suggestions. Although I love the gray tiles with the black tiles around the perimeter I think I should have gotten all black tiles because it hides the dirt and discolorations better.

Depending on what is causing the staining determines what you will want to use to clean them. If tar is causing the staining, then we suggest using Purple Power which can be purchased at a local retail outlet. If the tires are causing the staining, then the only solution would be to replace the grey tiles where your tires are parked with black tiles. To find the appropriate solution for your staining, we recommend contacting one of our Flooring Heroes via phone, chat or email and they will be able to assist you with your needs.