So I had my car parked outside, not being used, for a few months with a Tesla car cover over it. When I took the cover off, I had a nasty surprise when I realized a family of rodents had decided the wheel well and under frunk areas were great places to live. I'm in the process of cleaning it now, but so far I've had to take the wheels off, remove the wheel well covers, and take apart the frunk to access all the areas the rodents got into. Dirty, smelly mess. I live in the San Diego region, which is rodent central for anything outdoors.
So beware - that car cover works great, but it may hide a lot of other stuff going on!