As Reed and Malloy are about to stop Archer's truck, Malloy turns on the red lights. Then there's a long shot of the police car coming to a stop sign and the lights are not on. After the car turns, the lights go on again.
Not sure if it is continuity, but when Reed & Malloy pull up in the AMC Matador patrol car on the prowler call, a "curb feeler" is visible in front of the right-front tire. No LAPD car ever had curb feelers on them.
18 minutes in, Reed, off screen, identifies a pickup as a 1981 (series filmed in 1972) Tacoma which is not only odd for being 9 years off but also that the Toyota Tacoma wasn't built until 1995. (Reed says "1981 Tacoma" which was not the description of the truck, it was the address.)
As he and Wells are talking in the locker room, Reed is changing the ammunition in his handgun as it has been in-service for 6 months. There is a close-up of his hand showing the cartridges. The cartridges have dimpled primers, indicating that they are non-firing dummy rounds.