As a total klutz I can tell you the same thing Bri did.

My son (now 18) is a springboard/platform diver and trains over 40 hrs per week with an Olympic coach. When he first started diving and was learning to do land flips he thought it was so fun and cool to try them on regular ground... but he’s been at it awhile now and the facility where he trains daily has a huge springy floor like the gymnasts use. He will NOT do them on bare ground anymore now that he knows how different it feels and how hard it is on his joints to not have a proper springy floor. (His only exception is doing a single back flip at every sandy beach we vacation at so he can post a video of it on social media. LOL!) He’s just had too many injuries with his regular training that he won’t risk it on a subpar surface now.

Thank you for your responses. How about some kind of portable floor mat that she can easily put away to the side when done with her practice? Any recommendations or suggestions for that? TIA.

She may get more exercise putting the mat away than practicing dance.

I'm sorry but there isn't an easy answer to this. Cars are heavy and their tires are made of rubber. A dance floor will have to be "sprung" (some can be as high as 2 feet off the ground when properly constructed....using horse hair). Once "sprung" a floor like this should NOT be sitting underneath 2 tonnes of automobile (the "sprung" gets crushed and you end up with expensive yet damaged dance floor = useless).

Then there is the damage the rubber in the tires will do to ANY finish that is sitting on the floor. Rubber damages just about everything out there. The only thing I would put underneath rubber = concrete, dirt, stone or in a pinch epoxy. You will notice that none of those are good for dance.

It would be cheaper to "build out" the garage as a dance studio and then park on the street or in the driveway. That's about the only way the two will work together.

The other option: a professionally designed and constructed "temporary" floor (like the one's you see on TV being used for professional basketball courts). These floors are designed to be removed (by a crew of 15-20 people) after each set of games (teams go on the road and the facility is used for trade shows, beauty pageants, etc). They are expensive to design, expensive to install, expensive to maintain and physically very hard to remove/replace using one set of hands....or even 3 sets of hands. It would be financially easier to deal with if you did an addition to the home. It would cost less than one of these floors.

What @Bri said. Do not risk your daughter's musculoskeletal system by allowing her to practice on concrete.

I've work with ABT and other companies so have some passing knowledge of this. You can do something that has a dance surface on top of 3 or so layers of foam of specific densities. It's not cheap and could take a bit to set up but it'd work. You'd need to search for what each of the materials is and how they are layered.

You could possibly also do something that lowers down from the ceiling.

Better yet, find a dance studio that she can ride her bicycle to. The riding will be good for her as will the social interaction with others while she practices.

Update: we have had vinyltrax for some time now and its working out well