When Hooker & Romano begin the pursuit of the blue & white 4x4 that was stopped at the traffic light, the overhead lights on the police car are flashing. In the following scene, they are not flashing and Romano bends over to turn them on & they start flashing.
The man in the chicken suit (where Ramano gets shot) was in the western San Fernando Valley are of Los Angeles (see filming locations). Hooker & Romano consistently identify themselves as "4 Adam 30". The "4" is the Boyle Heights division located at 2111 East 1st Street 30 miles (48 kilometers) away out of their patrol area. The closest station to that intersection is #21 Topanga Community station at 21501 Schoenborn Street 91304 only 4.1 miles away. So the format for any patrol car in that area would have been 21-Adam-41, with 41 being the section of the division, in this case, 41. This format is explained in Log 15: Exactly 100 Yards (1969)(#2.1).