When MacGyver cuts the rear seat covering to get to the padding, he cuts 3 sides of a square and folds the covering down. Later when the car rolls into the ghost town, the rear seat can be seen and the seat covering is cut like a "plus" symbol.
The shotgun pellet holes that the lead bad guy shoots into the Cadillac's trunk disappear in subsequent scenes.
When the Cadillac broke down, it rolled up to a mound of dirt as high as the bumper. Yet, when MacGyver pushed it to the town, the car moved forward with no resistance.
The car rolls up to some low shrubs, not a dirt mount. It is conceivable MacGyver was able to push the car without resistance.
After MacGyver removes the muffler from the car, when they drive there is no difference in the sound. Without a muffler it should have made a very loud racket.
Actor who plays "Tony" -- MacGyver's contact who has infiltrated the mob and who is shot dead in front of MacGyver -- is not credited.
The characters Guy & June Roberts are asking each other trivia questions in which they state that a young Andy Williams dubbed Lauren Bacall's voice in To Have and Have Not. This has been disproved.