I think the last week of August is an alright time, historically its lower crowds than the first few weeks of August. Kids start going back to school, and even those who haven't started are getting ready to and the park has longer hours than in Sept on the weekdays. Will the opening of cars land and AP's being unblocked the week before mean there will be a rush to Carsland those last two weeks of August. Maybe, maybe not. I'd be surprised if it was more crowded than the rest of the summer and Disney does reduce hours somewhat so I think they think it will be less crowded.