Factual error: When they are at the Cadillac dealership, taking delivery on a car in 1956, the American flag in the background is incorrect. It should have been a 48 star flag, not a 50 star flag.
Factual error: As Miss Daisy is walking to the trolley stop to go to the Piggy Wiggly market, one of the houses in the background has modern skylights on it, and both are modern homes from post-1948.
Factual error: While driving Miss Daisy across Alabama, mountains are seen to the north as the car moves across the screen from left to right. This would mean that they were headed east or back to Georgia and not south and west to Mobile, Alabama.