Corrected entry: When the boys see Neil's car in his driveway, it has a registration plate. However Neil then says that it isn't completely built yet and doesn't have an engine. A car cannot have a registration plate if it hasn't had an engine installed, because the fuel type and emissions of the engine are required data for the registration process.
Corrected entry: The episode features Simon helping Carly with a subject he isn't taking, sociology - it's constantly mentioned about how he doesn't study it, but the exam he is given in the hall towards the end of the episode is titled 'Sociology' suggesting he does in fact take the subject.
Corrected entry: When Mr Kennedy places the towel around Neil's shoulders, you hear Mr Gilbert say 'John' although you can see that his mouth does not move.
Correction: What Neil says earlier in the episode is "I got a car... Last weekend" - there is no mention of it not being built, or even working. What Neil also says later in the episode is "I ain't got it [the car] going yet - it don't work... [My mechanic] Dave's trying to find me [an engine]". Based on Neil's intelligence as presented in the show its entirely plausible he's bought a car second hand that doesn't work or has stopped working. The number plate would have been assigned to the vehicle when it was registered new, and doesn't change when the car changes owner.
Neil Jones