Car cover
Personally I would look for one that is suspended above the car, like by a hoop of PVC pipe
Yes, for long-term outdoor storage that would be the best solution. But it may not be practical for a daily or frequent driver.
The biggest problem with car covers is once they get wet, you have to take them off the car, but then you have this huge, heavy, soggy thing to deal with. And even if it fits in your dryer, you can't put it back on until the car is bone dry. That might be weeks or months in Oregon, say.
The silver sunshade covers don't absorb water, but they trap condensation underneath, so it's the same problem minus the heavy, soggy part.
Really, if it's raining, it's better to just let the car sit uncovered. Then put the cover on when it's dry to keep the sun and dust off.