I go out of town for a week or so maybe four times a year. My Model S will be parked in my garage at home during these periods and I'd like to keep it covered to prevent dust accumulation. I'm hesitant to spend $400 on an indoor cover to use only a handful of times. Is it reasonable to just (gently) throw a couple cotton bedsheets over the car? Yeah, it's a little ghetto but I think they might do the job and would be quick to put on and take off. Do I need to be worried about leaving the wheels or any other areas open for heat dissipation? How many king-sized flat sheets do you think it would take to cover a Model S?