I remember my first 2-3 years of driving you still had to have a tax disc, I always thought it was a bit of a backwards step when they did away with them. Most of the time when I was younger my cars were never taxed quite often a few months overdue & the most effective thing to do was to get a small amount of petrol on a rag & clean the residue off the windscreen where the tax disc had been, I used to get pulled over quite a lot when I was younger

& not one of those officers ever look at the windscreen so I always got away with it

you were always more likely to get caught with the expired tax disc still in the windscreen, my dad's best mate had a Fiat Croma Turbo & he got chased by the boys in blue, got to 135mph & got away from them only for them to catch up with him at the level crossing when the barriers were down

it was only after they were there with him for an hour & a half that one of them looked at the clean windscreen & realised there was no tax disc