You can’t just bust out a sound meter and take a reading. There are so many factors that it makes it unenforceable, because at the end of the day the burden of proof would still be placed on the enforcement arm that it was that vehicle. How do you control for ambient noise? Distance? Temperature? It is just unenforceable to make a dB level a mark.

If your car goes pop pop pop, though, I think you need to have your car taken away, and maybe your freedom, because you’re just an asshole.