The headlights on Colson's Lincoln change constantly throughout the show. Sometimes there are 2 round headlights, other times there are 4 rectangular headlights.
In the opening sequences, the drug kingpin arrives in a Lincoln with one headlight on each side and flees in one with two headlights on each side.
At about 6:00, Romano and Hooker are in the patrol car and a car passes them while they are in "hot pursuit" of the drug dealer.
Patrol officers don't typically go on undercover surveillance operations, especially in uniform and in marked patrol cars.