Unquestionable enhancements to the overall chorus emitted through the Dinan system transcend all modes making the vehicle a delight to drive and enjoy. However, for those that wish to have options to limit the extraordinary soundtrack for late night or early morning arrivals/departures (or any number of other reasons) factory valve control is retained. This effectively makes the system behave similarly to a straight-pipe system that promotes maximum flow and volume when the valve is open and emit more subdued resonant vocals when the valve is closed, and exhaust gases are wholly redirected through the muffler. It is the perfect blend of civility when not pushing the car or the full spectrum of auditory delight when in it. No matter the situation, the Dinan valved cat-back exhaust system is the answer for the discerning enthusiast looking for sound without sacrifice.