I have a carport, its lattice on one side. There`s some random sh!t that falls out of the gap in the ceiling out there, dunno wtf it is but I don`t want it in my vent intake. I use 2 covers, a sexy velour type one and a parachute lookin one that's supposedly water proof. I used to have just the plastic one and I`d put sheets on the car before fitting but in was a pain in the arse speshly after polishing so I got the velour one. Now, I do not drive my car throught the week. lol I`ve not driven it for 2 weeks. So, fitting and refitting the covers ins`t too much bother. Obviously the car needs to be clean to fit them, so I need to factor that into planning. The covers work for me, I`ll pull them off tomo morning and the car is clean. Typically, never once have I seen cat footrpints on the cover..