I had a similar problem when I lived in an appartment complex a very long time ago with a cat that used to sleep on my hood and leave prints and hair. I was working in the constuction business at the time and we used Tyvek sheeting as a vapor barrior in the homes being built. I used a large piece on my hood secured with a couple cheap magnets. The stuff is very 'stiff' and makes a 'crinkling' or 'crunching' sound (like a piece of mylar or plastic wrapping paper) which I suspect the cat did not like the sound of when it walked on the material since it kept it away for a while.
Maybe cellophane wrapping paper or some aluminum foil might do the trick?
