My experience of MOT's is that most cars can pass fairly easily as long as a car is well after. I briefly worked in a garage when I was younger and some of the sheds we had in the day before an MOT to give a once over was about 50% of the jobs and they rarely failed.
I'd I remember rightly, Germany have a far more rigorous equivilent, of which would probably remove 25% of the cars in the UK which are on the road.
I can't justify buying a car new (unless it was under £15,000 and even then ). The quality of second hand cars compared to 20 year ago is huge. Also what puts me off is depreciation. A guy at work paid the best part of £30,000 for an Audi S3 last year. It's probably worth less than £20,000 now.