Re: Alas
Unregulated non-OEM replacement parts may mean that a vehicle does not meet safety standards, clean air standards, etc. The OEM parts have to comply because the auto maker is required to meet standards/regulations.
Brake discs come to mind - probably don't want them made out of pot metal rather than iron.
Flashing the firmware in the EMS which can improve performance at the expense of clean air and fuel consumption. Of course, if you have a Volkswagen...
Biting the hand that feeds IT
