Just remember, most of the "police" cars that you see on TV are really studio cars that are rented out. The radios inside do not work most of the time as they are props. Some are real but they are typically in the background (far enough so the city seal does show which is the quickest way to spot a studio car).
Patrol supervisors, in Adam-12 days, might have up to three radios. The first would be their division radio (one of the main dispatch freq's with the divisional talkback freq), the second was the "cheater" which allow the supervisor to monitor the talkback freq, and some had a third radio for the two main tactical freq's (particularly the station wagons which were used as mobile command posts).
ASD (Air Support Division) did have a station wagon in the Adam-12 days that did have an aircraft radio that was used in field ops as well as accident investigation.
To have a handheld radio ("CC unit") in those days was rare unless you were working a special event.
Wow, have the times changed.