Factual error: When Harry is standing on the ceiling fan, the young boy pulls the lever backwards to increase the speed. If you read the side of the lever, you can see that the boy is actually pulling the lever to the slow direction. (00:40:30)
Audio problem: When Harry and Nikki are driving in the vintage speedster with no brakes, Nikki is heard saying "same old family crap", but her lips mouth "same old family shit".
Other mistake: When Harry is being spun round on the ceiling fan you can see that they aren't moving fast enough to hold his body in a stretched out position,especially considering his bulk.