I've been an MoT tester for 28 yrs, having carried out 15,000+ tests. Cars these days are incredibly reliable compared the ones I was working on in the early seventies. It wasn't unusual for a vehicle to be dangerously corroded within 5yrs back then. Steering components were nothing like as good. These days a car can run 150,000 miles with neglible wear to steering gear etc. If properly warmed up beforehand, very few cars fail the emissions test. A 1960s or 70's car in the shop now seems to make your eyes water if you stand near the tailpipe.Tyre longevity then was very poor compared to now. These days most 3yr old cars pass easily, usually failing only on minor consumables like bulbs and wiper blades.