A local guy has a decent driver quality classic '70 Camaro he leaves parked in front of his home. It has a sunroof somebody installed aftermarket that apparently leaked.

He threw a blue plastic tarp on top of the car and tied it to the car through the grommets. For about 2 weeks it sat outside with the tarp on it.

He fixed the sunroof... now the Camaro has the clear coat peeling off where the tarp was, and the yellow paint on the car has blue marks where the tarp was tied down.

Tarps are a bad idea, even in a dry climate.