I've briefly touched nearly 80mph in a car, but not deliberately, probably when overtaking a clump of slower traffic in the inside and middle lanes* of a motorway.
I value my driving-licence and insurance - and my and others' lives - too much to wilfully break the speed limit, and have no wish to show off.
The limits are 70mph on motorways and dual-carriageways, 60mph otherwise on the ordinary roads outside of built-up areas, unless signed as lower.
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* Some British drivers call the normal divisions of each carriageway on a motorway, the "slow, middle and fast" lanes; but wrongly. Properly, they are the "inside" (adjacent to the "hard shoulder" and verge), "middle" and "outside", lanes.