I could be wrong, but think that unless you are a resort guest with a parking pass, you will need to pay the $6 (or is it more?) per day for parking at WDW. Most of the resorts have restricted lots with guards and make sure that you are parking there either as a resort guest or going to a restaurant on-site (and then you will be allowed only to park for a 3-hr limit).
This was the case when we were there in March 2003.