As everybody has commented, it's one rule for Thais and another for farangs. Illegal exhausts are one thing, defective/illegal brakes on Thai pick-ups, trucks, buses and cars are lethal weapons in the hands of drivers with no sense of road craft or consideration for others. Stop a few of them, impound their vehicles (with no back-handers to get off the offence) and I'll start to take the RTP seriously.