When Jon cuts out the seat belt of the squad car it's brown/tan. When he ties it to the car hanging over the cliff it turn black and gets longer.
Just before the car goes over the cliff, the passenger door is wide open, but as it goes over the cliff, the passenger door is closed and only the driver door is open.
Ponch has been out, injured, with a cast and sling to his right arm. At the end of the episode, when he comes back to work, his right arm is still in a sling. He is not wearing his gun belt, but has a service revolver in a holster on his regular belt. This is positioned on the left hip, as a right hand draw (cross body). There is NO way Ponch could use his injured right arm to draw, and, if he used his left, the firearm would be upside down (and this could be very dangerous to the police officer, until he could reverse it to the correct position).
During the final pursuit in the maintenance yard, the gates are shown to be pushed closed and not secured, with one even swinging partially open in the direction of the police car's travel. The police car being chased could easily have gone through them.
When speaking about the police car, the mechanic says one of the problems with it is the clutch. That model of sedan had no manual transmission option, so it had no clutch.
After John stops the movers from loading his furniture into the moving truck, they go inside and apparently forget about moving his furniture back to his apartment.