Police were M2 +2 M2ZH was Edinburgh and M2BD as in Zed Victor 1 to BD
I remember the first night that Z Cars was shown on TV, I had a choice of staying home to watch the new series or meeting the girl-friend-de-jour. Z Cars didn't win that one, but the following furore in the papers about how the police were depicted (wife-beating, etc) publicized the series no end, and I swapped evenings so I could see future episodes. Lancashire Police withdrew their co-operation in protest at the coverage.
A few years later I had cause to be grateful for the aid of a Z car. Heading south on the M6 somewhere south of Preston my 348cc Velocette had a front-wheel puncture, and I didn't have the kit needed to repair it. Nonetheless, while I was taking the wheel out and pondering my next steps, a Z car pulled up and one of the officers asked what the matter was, and went on to say that they were on a call but would be back in 30 minutes or so.
I sat in the warm sunshine watching the traffic go by, until the returning Z car pulled up opposite on the hard shoulder of the northbound carriageway. One officer ran across to the median, and called me across. Picking up my wheel and tools, I legged it over both carriageways, dumped the wheel, etc in the boot of the Zodiac, and we sped off at well over the ton, until they turned off and dropped me at a garage close by the motorway.
I think I was generously given a repair kit, and anyway made short work of the job, thumbing a lift back to my waiting Velo and the rest of the
200-mile journey home. Next day was a week day, so leaving the lab in the evening I filled up at a nearby garage, and I'd just pulled away into the traffic when the front inner tube exploded leaving me with very little control of the machine. Being a skilled biker I didn't fall off and so spill petrol or suffer any injuries and brought the machine to a halt. I had to get buses and a train to get home.
I had a spare tube at home so dad gave me lift back to my machine. I did the business and was soon back on the road. Later examination of the offending tyre showed a tiny manufacturing defect that when in use was slowly abrading a very small area in the inner tube, which as a result had finally let go in a big way - fortunately at low speed rather than those of the motorway.
I'm still grateful to those two Z-car officers for their help and assistance.