In the closing scene the Bentley MkVI car has a Rolls-Royce bumper with the "RR" badge prominently showing.
When Charlie and Billie are walking in the school there's a poster on the wall that reads, "DECATHALON TRYOUTS!! FRIDAY." The correct spelling is decathlon.
During the scene where Lori is in the principal's office, you can see modern vehicles through the window. At the decathlon, a modern minivan is in the parking lot.
Tracy Morgan's character and his friend breakdance. Dancing is outlawed, yet no one says anything.