Chapter Four: The Body - S1-E4
Continuity mistake: Right after Nancy puts together the torn photo of Barb at the pool it cuts to Dr. Brennan and crew in hazmat suits. At the beginning of the shot when they try to reach Shepard on the comms, the digital clock reads 6:54:08. After Brennan says "Try him again.", the shot has the clock blurred in the background as 6:40 something, and a bit later it reads 6:40:55. (00:27:20 - 00:27:54)
Chapter Seven: The Massacre at Hawkins Lab - S4-E7
Continuity mistake: Eddie is still wearing a denim vest he took off his body and threw at Steve a few seconds earlier. When the camera cuts away and back, the vest is gone again. (00:15:19)
Chapter One: Suzie, Do You Copy? - S3-E1
Continuity mistake: In Bruce's hamburger the salad is on the bottom and the bacon is on the top, in the next shot the salad is on the top and the bacon has disappeared, replaced with ketchup. (00:23:05 - 00:27:10)
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.