I've never had an issue doing ~80 on a motorway (except in my HGV!) I was stopped once on the M5 in Somerset, I had been travelling around 80 when I was pulled over, it turned out my numberplate was loose (only held on with double sided tape) and that was the reason I was stopped.
I freely mentioned my speed to the officer when he asked me how fast I was going and he said as - at the time - I was driving a BMW 7 Series that had good tyres & was in good condition, he had no issue, especially given i was flowing with everybody else as opposed to trying to make progress through the traffic as such.
He said, the road conditions, speed, condition of the car / type of car were big considerations, the biggest was the attitude of the driver once being spoken too.
Food for thought.
That's reassuring. I just returned from a trip around Europe (~3500 miles in 10 days) and didn't see many police around but I'd rather see more considerate police and less brain-dead cameras around. I got to silly speeds on an empty autobahn a few days ago and it's surprising how slow cruising at 100mph seems afterwards!
I feel like the car and condition of the car is an important factor that is mostly ignored by many.