Car covers, see an excellent selection showing. A must for outdoor car storage- 2 types: The solid and breathable (porous), I have used both with very good outcomes. The issue here is the underside exposed to maybe paving but many times damp earth.

Seems that to park the car on a tarp staked down with long nails &/fender washers works ideally. Keeps the dampness out from underneath and along with a draped down cover car can sit easily through a winter ( perfect dirt square for spring garden when removed).

The down side is covers can do a scratch up job on finishes if car is covered when dirty or often. My other car is out in the shed, uncovered. It sits for 6 months and no reason at all to not just let sit. No dust and isolated, have yet to see a mouse (release traps). Brand new cover that came with car never used. Well too, trickle charger on battery w/hood up and will not start/run at all through season. Decided it's the lesser of the 2 evils versus all those dry first startups to exercise motor, fluids and which else?