The movie depicts Junior's father as being arrested for producing moonshine. In reality, it was Junior himself that was arrested and sentenced. In 1956, federal tax agents found Johnson working at his father's moonshine still in Wilkes County; they arrested him. Many local residents believed the raid was done in revenge for the agent's inability to catch Johnson delivering moonshine on local highways; this is depicted in the movie when we see the local law enforcement busting up his father's still. Junior Johnson was convicted of moon-shining and was sent to prison in Chillicothe, Ohio. He served 11 months of a two-year sentence.
At the Hickory (NC) Motor Speedway (where Junior first met Marge), behind and above turns 1 and 2 is a real cemetery and, if a funeral is scheduled during the races, all on-track activity is halted (and the motors turned off) until the funeral is completed.
Junior Johnson is credited with inventing the "bootleg turn", in which a driver escapes a pursuer by sharply putting his speeding car into a 180-degree turn, using the parking or emergency brake, on the highway, then speeding off in the opposite direction before his pursuer can turn around. In the movie this is used to great effect twice on the same police officer: when he first encounters the officer he does a 180 and the chase begins and then uses the "bootleg turn" once more effectively causing the officer to embank his car on the road.
The #12 red and gold NASCAR Chevy Monte Carlo Jeff Bridges drives at the end of the film was actually Bobby Allison's well known and winning Coca-Cola sponsored car owned by Junior Johnson.