At the end, the camera is behind Tony's car as he approaches a green light and starts to make a left turn. There's a car in the oncoming lane that makes a left turn just as Tony does. Midway through the turn, the camera then switches to a hood view into Tony's car, the other car that was turning left in the opposite direction is no longer there.
After Justin is taken off the ventilator (particularly as he's talking to Jessica), he's given supplemental oxygen through a nasal cannular line. The lines for this type of oxygen system would be routed around the ears and then cinched beneath the chin to prevent any pinch points as the patient moves in bed. As seen from the left side of Justin's head, the tube is wrapped straight around the back of his head, which would disrupt the flow of oxygen as he rests his head on the pillow.
When Clay receives the box of tapes from Mrs. Baker, after it's been removed from evidence, there are only 6 tapes in the box. For the 13 sides that Hannah had recorded, plus Bryce's confession, there should have been 7 tapes.
As Tony and Clay pull away near the end, you see their CA license plate, 3IDW674, then the camera switches to Clay's parents and Caleb waving. As Clay's mom steps to the side, you see part of the license plate on Caleb's car. It also ends in 674, more than likely because it's the same plate.