Need advice on garage floor

I had to have the foundation on my garage repaired. In order to do so, they needed to bust out the concrete on half of the garage. I cant afford to have the concrete replaced right now, so I just put gravel in. I'm not sure when I can get the concrete work done, but it may be more than a year.

A friend of mine told me that just having gravel in there will allow moisture from the ground to come up and cause my car to rust, so I'd just like some opinions on whether that is true or not.

If its true, could I just lay a tarp on the ground and park my car on that to keep the moisture from coming up directly under the car?
Author: admin