would a dehumidifier be a good idea to put in the garage with my car?
they basicly take the water out the air.

http://www.meaco.com/guide.html

would it help stop rust?

 

Only if you are a multi-millionaire to afford the electricity bill. De-humidifiers drain a lot of electricity. Used to have one in the god-parents garage as they have eight 1910-1930 motorbikes stored there and pre-fab garages tend to generate a lot of condensation. After the first quarter, their electricity bill came in something like Ł150 over what it normally was.

Suffice to say, it now runs on a timer for an hour or so a day just to keep the worst condensation away.

 

forget the humidifier.its all to do with air circulation.use 2 movement fans 1 at the back 1 at the front.never had a problem with this method