After reading through this thread and seeing the innards of the stock muffler, I decided to replace mine. I went with Magnaflow #11225. Had it installed last week for $111 (muffler and labor) at Modern Automotive Performance (employee pricing bc my brother works there). I’ve had it on for about 300 miles. It’s mellowed out a bit, kinda loud if I step on it. Not much if any increase in HP. I will report back on MPG.