My '88 Corvette drives daily and had factory Hi-Po mufflers which were long overdue to replace as they were very noisy/humming. I've put glass bags on it that were too noisy for everyday use like the Raptors I've tried. I ordered/installed them and they are amazing with the difference in throttle response, torque at low speeds and acceleration at overtake speeds. Despite the idle volume, the overall sound is good with no hum.