http://www.hagerty.com/classic-car-articles-resources/HowTo/Storage-and-Transportation/All-articles/2009/12/02/Tips-to-Keep-Mice-out-of-Stored-Cars?utm_source=ExactTarget&utm_medium=email&utm_term=&utm_content=&utm_campaign=Hagerty%20Weekly%20News%2011-27-2013

They can really wreck a car interior in a hurry.  When my dad brought home the '69 Convertible in July, he also brought home a family of mice with it.  They shredded some paperwork he left in the back, and built a very comfortable nest under the driver's seat. 

Caught four of the little guys in two days.  If you use traps, check them daily!  I skipped one day, and the smell was pretty bad... 

I'm shocked..SHOCKED I tell you, to see that NO-one mentioned the most effective varmit repellant to keep in the garage, or in the car.....it's all I use, and it works quite well. Also works as the perfect anti-theft device.....

I made the mistake of using a glue trap in my '75. I caught the mouse but he got the last laugh. He squirmed around enough to flip the trap upside down on the carpet. I spent hours trying to get that glue out of the carpet.

That is too cruel. Still pretty funny, thou.

Joel, Thanks for the suggestion. I'm sure your method is very effective but I think I'll stick with the dryer sheets.  Besides, I don't think those things grow around here.

I'll be more than happy to send ya a few...dozen....

We have rattlesnakes around here but the darned things sleep all winter so they're not much good.

I personally like this one:

Put your car on jackstands sitting in oil drain pans. Put about an inch of oil in the pans. Mice will not cross the oil. It's safe for pets. They won't drink the oil where they will drink anti-freeze. If you do not take the tires off be sure they are high enough off the floor that mice can't climb them. Same thing with the cover, leave nothing hanging down they could use to access the car.                 

|UPDATED|12/1/2013 4:35:19 PM (AZT)|/UPDATED|

Tis was a friends vette stored in his garage