One solution for the dirty interior is the convertible car cover that Bavarian Automotive sells. It's about $90 and goes on very easily. I use mine when I'm leaving the car for a couple of hours or more. It will not keep it dry during a downpour, but will work in a quick drizzle. The best thing is it keeps the tree sap, the bird droppings, and other stuff off the interior. It also keeps the seats and steering wheel very cool. When not in use, it rolls up easily and stays in the trunk. Give it a look.