I took line 15 to the ARTIC - Anaheim train station. Take the bus, its way way easier than taking the car. The ART bus stops are right beside the bag security lines at the Harbour Boulvard side of the Disney Esplanade. Once through security checks you are within a few feet of the entrance turnstiles.
Compare that with driving into Mickey and Friends parking structure, driving round and round, up and up each level to park, walking from your park spot to the escalator down to ground level, then going through security bag check, then waiting for a tram to Downtown Disney, then walking through Downtown Disney to the entrance turnstiles.