You can use the lounge only if you booked your trip through AAA. You'll be given a voucher that allows you admission, so to speak. The lounge is sort of behind the Carousel of Progress. There's a gate between the COP and the Galaxy Theater with a AAA logo on it - go through the gate and down a path to the AAA lounge. The voucher entitles you to a free soda and use of their facilities. They have really nice restrooms and a lounge area where you can hang out, drink your soda and watch Disney movies on their TV. They also have loads of AAA travel info