They nearly always had a passenger back then. Most cops in the 1970s were very fair if they stopped us here. Often just asked to see the licence etc. I did get one walking cop stop me in a Sunbeam convertible when i was 18. I think he was a bit jealous as he checked the entire car before declaring i had a slight exhaust leak at the manifold. The gasket had failed. He then booked me so i had to plead guilty to allowing exhaust gases to escape and fined 5 quid. I doubt any would book you for a failed gasket now.
I also got chased by 2 cars in my Morris Cooper mini. I knew they were behind so drove at 29mph. They said i had been speeding a few minutes ago. Well, i was but there were no cameras or equipment to measure speed in 1972 so off i went scot free.
Back in the early 70s with very few cars out at night, we had become racing drivers in the dark. I wrote off one car and my Brother wrote off three.
I hit a tree in a Hillman Minx
He turned a mini over on ice
Hit a large garden wall on a bend in a hillman Minx
Turned an MG midget upside down
Eventually, we all slowed down a bit