I think, but am not sure since I've never had a car in WDW, that you can only park at a resort for 3 hours if you're not staying at that resort. So you'd run the risk of something happening to your car while you were at the park (not sure if they ticket you or how they enforce that limit). Also, if you do park there with the intention of moving your car later, you have a great chance of getting to the park for EE and not being allowed in because they're checking for resort IDs. Though they don't always do this, they've done it more times than they haven't over the past 2 years.