How to store car without rodent infestation?

I thought that I would put this out to everyone to get some good ideas. I'm storing my dart at a local storage shed and have had a past problem with mice in the headliner and heating ducts. The storage area has a concrete floor and stays dry so I don't have to worry about much rust but those damn mice. I have cleaned out the car once and cleaned up the headliner but I want to avoid any future problems. Please share any success stories from traps to chemicals, etc.

Carl