Officer Jim Street and his partner are seen on patrol in a 1974 Dodge police car. however, when they arrive at the scene of a call that they receive, they are in a 1974 Ford police car.
In the apartment scene in which the worst of the bad guys is watching a violent car chase on TV, the opening pans in on a simple portable TV (looks like a B&W set converted with a color tube) on a metal stand. The view then shifts to the kitchen for a few minutes and when it returns to the living room, the guy is watching a wooden console with a remote control.
After Harrelson tells the men in the squad room to be clean shaven by morning an officer appears in two subsequent scenes (the rifle range and when being given a demonstration of the S.W.A.T Van) an officer appears with a mustache.