If you couldn’t override it then I’d be very worried, as they would be downright dangerous, but you can by just putting your foot down hard on the accelerator which is what you would do anyway when overtaking. So a system that by default stops you speeding but allows you to override it would be fine with me. However, given the poor standards of driving that you see nowadays, I can see more head on collisions with people taking too long to overtake. For example, if you are on a road with a 60mph limit and you come up behind someone doing 55mph, if you only overtake them at 60mph you are on the wrong side of the road for far too long to overtake safely. I can see a lot of drivers being reluctant to use kick down (or equivalent) and therefore performing very dangerous overtaking manoeuvres.