Brian's recent update of the FAQ section has spurred me on to make a visual record of all the patrol cars that appeared in Dukes. You'll find much of this information in other threads on HNet, but I wanted to collect it together with pictures (they say a picture is worth a thousand words!). Although most of the non-Hazzard cars were Dodge Coronets/Monacos or Plymouth Furys, I intend to include them to show their different liveries. I have recreated some of these already in the Rosco's Patrol Car thread in Fan Art.
We'll start with season 1. This had the largest variation, with different cars being used throughout the season, and the continuity was appalling - often a patrol car changes make and model several times mid-chase. Some of these early cars even pop up in later seasons when footage is re-used. You can see why they standardized the cars (and most of the cast's costumes) in later seasons.
The first is from 'One Armed Bandits'. It's a 1970 Dodge Polara. This car appears in the opening credits; first when the show's title appears, and then pulling up in front of the pile of dirt for the Lee 1 jump.
The other patrol car in 'One Armed Bandits' is a 1975 Dodge Monaco (very similar to the 1974 Dodge Monaco that appears in The Blues Brothers). In case you thought that I was mistaken about the patrol car used in the Lee 1 jump, the car that pulls up is the Polara (see above), but the patrol car that gets jumped was this Monaco - just one example of the bad continuity mentioned at the start of this post.
'Daisy's Song' introduces us to the Atlanta Police. They have several patrol cars, all 1975/76 Plymouth Furys.
By 'Mary Kaye's Baby' another Hazzard Patrol car appears - a 1975 Plymouth Gran Fury missing the 'T' from the hood letters - unusual because later vehicles had their branding removed or covered with tape.