When Simon arrives home after passing his test he grabs the Nintendo out of his brother's hand and when the camera flips back to Simon the Nintendo is nowhere to be seen. It could be in his back pocket but the camera change did not leave enough time for this to happen.
When the boys are on the Nemesis Inferno Will sits at the front while the rest sit behind him. This leaves the right outside seat free. However, when the roller coaster is moving the mounted camera shows that Simon, Jay and Neil have all moved one seat to the rights meaning that Simon is now on the right outside seat instead of it being free.
When Simon is parking his car after arriving at Thorpe Park his car shows two different number plates on the front and the back of the car. The front shows "M335 ALP" and the back shows "M483 LTH", which was also the number plate of the hearse the car got stuck behind earlier.
Simon is having a driving lesson and is seen trying to reverse park between two cars (with cars at both the front and rear of the space being present). However, on a normal driving lesson a driving instructor will only ask you to park up with the front car present.
Simon is practicing parallel parking where there is a car in front of him and behind him. In an actual driving lesson, the instructor will only ask you to carry out a parallel park behind the lead vehicle and never between two vehicles.