Such dodgy practices were not uncommon, in my experience in remoter rural areas. But the demise of many "ye olde village garage" and the new computerized system clamped down on it, although I'm sure there may still be testers who turn a blind eye to some faults.

Near me any tester who gives dodgy passes risks a very rapid comeback = There's a roadside DVSA test site on the outskirts of town that does spot checks on suspicious vehicles.