When Lisa walks into the hotel room, she sits on a bed with rose petals arranged on it in a heart formation. Some of the petals move when she sits down, but in the next shot they are rearranged as though they hadn't moved at all. This happens a few times in different shots throughout the scene.
In the beginning scene, first day of school, tulips are blooming and tulips bloom in the spring, not in the fall.
In the acceptance letter from UCLA, "enclosed" is spelled "encolsed."
After Sam vomits out of the moonroof of the limousine onto the parents' car, their windshield is obscured, causing them to spin out and crash. After they crash, the shot is from outside the windshield, which is now perfectly clean.