Chapter Five: The Nina Project - S4-E5
Continuity mistake: The seat belt keeps appearing and reappearing on Nancy's shoulder as she's driving.
Chapter Five: The Flayed - S3-E5
Continuity mistake: When Robin takes the chemical container off Erica, in the shot of Erica saying "It could be useful", Robin is holding the container upright. In the next shot, it is being held at a rotated angle, then upright in the following shot. Two shots after that, the container is suddenly rotated again, then back to upright when the shot cuts. (00:17:25)
Chapter Five: The Flayed - S3-E5
Continuity mistake: Eleven and Mike are sitting next to each other at the hospital. Eleven looks to her left in one shot and the camera changes angles. She's now looking straight ahead and immediately looks to the left again.
Chapter One: Suzie, Do You Copy? - S3-E1
Continuity mistake: Steve is talking to Robin about striking out. Two girls come in and Robin encourages him to talk to them. In the first angle his shirt is lower and you can see his chest hair. Cut to the other side as he flips around to talk to the girls, and his shirt has moved up. (00:24:15)
Answer: They're both muscle cars, but that's about the extent of the similarities. But the 70's were filled with a lot of muscle cars, so some car models may look a bit like another's. Billy's car is a late 70's Chevy Camaro (probably a ‘79). Mad Max's car is a 1973 Ford Falcon XB GT. Incidentally, the Ford Falcon was produced by Ford Australia and wasn't an American car, or even sold in America (as in not sold at dealerships).
Bishop73
According to the experts its a Camaro '78 with added vented side fenders.