dose anyone know if using car chemistry inserts are street legal in NC, i read waht the DOT says and i have a fealing i will have to have a visible muffler to pass inspection.
Yep. As long as its quiet enough to keep you from gettin pulled over your fine. Like Jasrnold said there is no inspection once your car is 35 years old.
Their might be a db level that you have to meet. Here in cali its 95. If you stay below that they dont care what exhaust you run.