When Daisy steals Rosco's car, it is a 1974-77 Plymouth Gran Fury. In the chase, it bounces between the Gran Fury and a 1970 Dodge Monaco.
During the opening chase, Bo tells Luke to grab the sign, but it's actually during the final chase when Luke grabs the sign.
In the opening sequence, when the stolen police car makes the first jump, the license plate is on the left side of the car. The driver is clearly wearing a sheriff's uniform and a helmet. After the jump, the license plate goes back to the middle of the bumper and Cooter is driving the car.
In the first episode, the General Lee is either missing parts or has mismatched parts. As revealed by John Schneider in the DVD Commentary, the opening scenes of Bo and Luke in the General Lee, when they're chasing Cooter in Rosco's car, Luke (Tom Wopat) appears to be sitting lower in the seat than Bo. That was because there was no front passenger seat in the car at the time and Tom Wopat was actually sitting on a pad. Later on in the episode, when they're waiting to hijack the truckload of slot machines, we see that the General Lee has a blue steering wheel...but the car's interior is tan.
In some interior shots of Bo and Luke in the General Lee, you can clearly see that they are not really driving.
Towards the end, Bo and Luke are seen driving around town with Roscoe following them in his police car. During the chase, you can see another General Lee parked at a storefront.