When Harry is at the track watching Rowdy practice right before he meets Cole, the sky and surrounding atmosphere is VERY cloudy and foggy. When Cole enters the track and approaches the race car, the weather is now clear and sunny.
At Cole's first race at Daytona, the announcer called it the Firecracker 400. The Firecracker 400 was the name of this race from 1963 to 1984. It should have been called the Pepsi 400, as it was renamed for the third time in 1989.
During the race in North Wilkesboro, North Carolina, Russ Wheeler slams Coles car into the trackside wall and he spins off, Cole can clearly be heard saying, "Son-of-a-bitch!" and yet his lips don't move.
Near the end of the movie, just after the crew fixes "Cole"'s transmission and sends him back on the track, he pulls in front of the pace car as he exits pit road. Harry tells him to be at max speed at the drop of the green flag. Then you see the pace car pull off the track and the green flag drop. The exit to pit road at Daytona is between the Start/Finish line and Turn 1. Cole would be traveling at about 185mph, while the pace car and field are traveling at 65mph. He would've caught up to the back of the back of the pack before the pace car even made it to Turn 3 and Cole would've been at the tail end of the lead lap.
At the Dover, Delaware race, Cole enters pit road when another car pulls out in front of him. Cole has to slam on his brakes and then looses control. He is then seen wearing a white with red and blue trim fire suit as he says, "Oh, this gonna hurt." When he strikes the wall, it shows him in a fire suit with his team colors (green and black).
At the Daytona race before the big wreck, Cole Trickle is spun out by Rowdy Burns. Cole recovers and catches up to Rowdy. The camera pans out to show a long distance shot of Rowdy leading Cole, but the lead car is clearly the number 3 Goodwrench Chevy of Dale Earnhardt, not the 51 of Rowdy Burns. In fact the whole shot is from the 1990 Daytona 500 and the cars on second and third are Derrike Cope's Purolator Chevy and Terry Labonte's Skoal Oldsmobile.
When the cars are lined up to begin the final Daytona race, Wheeler's car is correctly in the pole position, toward the inside of the track, while Cole's car is a few rows back, on the outside. Just before the race begins, Wheeler and Cole glance at each other as though they are next to each other. In reality, they were not lined up close enough to see each other as directly as the camera angle presumes.
When Harry is teaching Cole about the car and tire wear, in the first scene discussing the tires, Harry's wearing a Georgia hat. When they switch to Harry's method of tire use, Harry's wearing a Florida hat.
At the very end of the film, when Cole and Harry are sitting on the pit wall talking, the wall is clearly draped with the Mello Yello and Hardee's colours. When the camera switches to them running down pit lane, the team colours are nowhere to be seen!
In the scene after Cole Trickle recovers from the spin out at the firecracker 400 and catching up to Rowdy Burns, he passes a #18 orange Hardees car, now Russ Wheeler and the Hardees car are not yet introduced until later in the film.
In the final race: The Daytona 500, Cole is at the back of the pack, now when Aldo Benedetti loses his hood and causes a pile up, Cole Trickle's #51 mello yello car can be seen near Benedetti's car and can also bee seen in the pile up, also Cole is in the back and just about to go through the crash, how can he be at two places at once or is there two cars?
When Rowdy gets mad that Cole is going to pass him and Rowdy says, "I'm going to put him in the wall," which would have summarily resulted in Rowdy being black flagged for the race (and probably more than one race after that), cars that are traveling at 200 miles per hour do not bounce off each other and keep going straight ahead. Cole's car, or Rowdy's car, would have hit the wall, spun off the track, flipped or rolled multiple times, smashing into a thousand pieces and taking several other cars out with them.
After the caution in the final race when Cole beats the pace car out of pit road, the race restarts with Wheeler, the leader, starting on the inside line. In reality, Wheeler's car should have been on the outside line, as lead-lap cars start on the outside and cars a lap down or more start on the inside.
In the scene where Cole and Rowdy line up at the stop light in opposite vehicles, Rowdy is in a Ford Taurus. When the light turns green, they both gun it and you see smoke coming form the tires of the Taurus. The smoke is coming from the rear tires. The Ford Taurus never came with a RWD option, they were all front wheel drive, thus the rear tires should not have smoked up.
After Cole sabotages Russ Wheeler's victory lap by wrecking his car, you can clearly see that the checkered flag hanging out Wheeler's window is secured in place rather than being held. It is clear from the in car camera of "Russ Wheeler" that the flag is somehow secured in place, and the window netting is still up.