As has been said, it won't happen... Too many companies will suffer, which will mean further unemployment and debt for the country/government, training will need to be given to those who are required to enforce it (police/mot testers etc) as they won't have the time to drive around stopping every single car thats modified, and that wouldn't be a small task in itself!

A lot of cars don't even exist in standard form, so what are they going to use as a benchmark?! Standard parts are no longer available for a lot of cars, meaning after market is the only option available.

I can however see a change in how modified cars are allowed, perhaps a one off extended test to make sure all the modifications fitted are safe as part of an extended MOT or something but beyond that, it wont happen.... if it does, I'll leave the UK. They've been trying to enforce the same thing with bikes for years, there are always ways around the system.

Every year there seems to be one of these come up, and every year the same debates happen over the forums. Look at the mess this country was in when the fuel crisis happened, do you think that people won't protest about being able to use/own/drive their modified cars?! No chance, in fact I would bet on more people protesting then they did over the fuel prices tbh...