For the meece problem, I am trying this stuff:
http://www.goodearthenterprises.com/freshcab.htmlI have several cars/trucks parked outside and the mice have been pretty bad this year. Too soon to tell if it's working though.
You can get a desicant to keep the moisture down at walmart, comes in a big tub and costs about 9-10 bucks and should last 3-4 months. The stuff works, I use it in my motor home to keep the mosture content down down in the storage basement.
I change the oil and over inflate the tires as mentioned.
I have heard that it isn't good to "unload the suspension for long periods as it can be worse than letting it sit loaded on the tires.
Full tank of gas with stabilizer.
A good wash and wax for the paint. Pay close attention to any body flanges that may be holding dirt/road debris, these will attract moisture and begin to rust. Some cars are worse than others for having these hidden areas for dirt to sit. Many cars have drain holes that can get clogged and allow moisture to sit also.
Most of the time, starting and ideleing a stored car won't bring the exhaust system up to temperature and you will wind up with condensation that will sit in the pipes and rust it out from the inside....................
There's my 2 cents.