I have a dosimeter in my car for this specific reason. I've also walked up to his police car and tested it at 95 db. GG officer. I've taken my cars to court. The police officer never shows up and I get my tickets waived.
2012 BMW M3 Coupe JZB/Fox Red DCT ZCP. Vorsteiner Double Sided Carbon Fiber CSL Boot Lid. Paint Match Grills, Side markers, Reflectors. Carbon Fiber Splitters. Lux Angel Eyes. Custom Rear Section Exhaust with valves. Next mod: Valentine 1