Here's another tip for those who don't drive your cars in the winter: Stuff steel wool in the tailpipes, not rags. Mice will chew through the rags, but won't go past the steel wool.
-Jeff
P.S. my year round '55 Ply is only 2 3/4" off the ground(dropped 5 in front, 4 in back), so when they can't get the plow started, they call me