I was searching some information on keeping the mice away and found this good article online, wrap the edge of the car with metal flashing on the floor in an upright position, this way no mice can get at your car. If you look at the pictures it makes sense. This is what I will be doing very soon, I also have a 4 post lift for my other car, but somehow the mice got in it last year and chewed a hole in my 68's headlliner, talk about pissed off!
Here is the link to that article I found, hope it helps
http://www.hastingsreserve.org/mammals/MiceInCars.html