aFe 49-36302-P MACH Force XP Cat-Back Exhaust System

In short, this is the BEST sounding exhaust I’ve ever put on a car — for the 135i it sounds absolutely sultry and wicked! As another reviewer pointed out, it has a great “sleeper” aspect to it. The tips are just enough larger than the stock system to make one think…hmmm….is that exhaust? But just cruising by, it’s only a hint that there might be something there, because it closely resembles the stock look — but, make no mistake, it’s FAR from stock, and when you get on it, or blast through a tunnel, the sleeper definitely awakens!I listened to a ton of sound clips for the N54 motor before choosing this one and I just thought it sounded the best — the cleanest, the deepest, the most aggressive at WOT, but not invasive during tame driving. Incredibly, it’s about HALF of what a lot of the other systems cost, so, wow, talk about deals! This sounds amazing, and costs less!It’s kinda rare that advertising delivers, but, in this case, when afe says it was actually designed with the tone in mind (specifically, the resonator is meant to produce a deeper note, with no rasp), they weren’t kidding. It has a very pleasant deep “burble” at idle, and sounds just like a better version of stock, when cruising around, but step on it, and it brings out a very smooth, “tuned” and completely aggressive growl. Sprinting off the line, it seriously howls! People snap their heads around to look, wondering what you’ve got under the hood, because it actually makes the car sound like it has far more going on, and, of course, it will only sound sweeter as other parts are added (downpipes, charge pipe, DCI, etc.).I think the best feature, besides the incredible notes it produces, is the fact that it produces no annoying “drone” inside the car. Honestly, that can get pretty old and, hey, in a Bimmer, part of the thrill is the luxury of the ride, so why disrupt that with a howling exhaust that drowns out the beautiful sound system? What’s nice is that it’s just enough louder than stock to give you that connection to the engine — telling us clearly what the N54 is doing, and that is an improvement over stock, for sure, especially for those who have a stick, and drive as much by ear as by feel. I hate cars I can’t hear, and for a stick shift, being able to be in tune with the revs is essential.The specs say it is an 11 hp gain, and pick up of torque as well. I’m not sure how adaptable the N54 ECU is — opinions seem to range widely on that, as is usually the case with opinions — but the butt dyno says it’s a bit quicker than before, nothing major, but you get past sixty in a hurry, and you sound great doing it! So, I’m HUGELY happy!HIGHLY RECOMMEND!!!!! Congratulations to afe on an AMAZING exhaust set up!!!