>>The principle is simple: just as you get to choose whatever after-market modification you want to make to your car,<< I'm sorry, but I stopped reading beyond

>>The principle is simple: just as you get to choose whatever after-market modification you want to make to your car,<< I'm sorry, but I stopped reading beyond that bit. There is no functioning government regulatory body in this world that would allow exhaust systems without catalytic converters or external wastegates, for example.