After Quagmire gets captured, stuffed in his trunk, and the car drives off, Peter and Joe stumble out of the bar. They exchange car keys. In the next scene Peter is driving the cop car and pulling Joe over who was driving Peter's car. In - "The Hand That Rocks the Wheelchair," Season 9, episode 12 - it can be seen that Joe modified his vehicle so he could drive it without needing the pedals; it has to be assumed that he did the same thing with his squad car. How would Peter be able to drive Joe's police car let alone Joe's inability to drive Peter's car? This scene shouldn't have even happened.