I was just curious if the frankencar and stock mufflers were the only ones out there that don't drone in the cabin. I need a muffler that doesn't drone due to distance driving and the amount of driving that I do. I have a full custom exhaust set up already with headers and no cats. I have a straight through muffler which was a big mistake. I was just curious if there were other mufflers out there that were quiet enough inside the cabin that it's not really noticeable.