I have a parking spot for my car, but it is weedy gravel. I've been warned that storing a car on grass is very bad because transpiration from the grass will rust out the car's underbody. Presumably this warning would also apply to my parking spot. I laid a tarp over the gravel, but since this allows pooled water to evaporate, it may not be much better. I did poke some holes in the tarp to allow some of the deeper pools to drain, but I hit the point of diminishing returns rather quickly.
For those of us without a paved surface, what is the best way to store a car? Is it worth it to build an inclined surface so that water will run off? It would seem to be relatively easy to do this with a big sheet of plywood and some 2x4s.
Is gravel itself a good place to store a car? It seems like some of the same problems presented by grass would be present — water would be evaporating up out of the soil, albeit at a slower rate.