Every peel and stick tile that I have ever seen always shrinks after being installed, and leaves you with nasty gaps between the tile. For anything to stick to concrete, the concrete must be clean, dust, and oil free, not to mention that it must be very smooth. I suggest that you consider one of the other products that is specifically made for concrete use. If you do a search, you will find more reading on the topic than you will have time to do in a week. It has been widely discussed in the past, and everyone has their own favorite method for covering concrete. Personally, I like clear sealer on concrete, and not too smooth a finish. The last thing that I want to be worrying about in the garage is falling on a slippery surface.