Gayest thing ever, they have one that you clamp onto your muffler and they also sell a horn/speaker system that you mount under your hood and the BOV sound comes out of the horn. And it actually cost over $100. It's shit like that, that really pisses me off. And people considering getting something like that shouldn't be doing anything to a car except driving it from point A to point B and nothing more. Your friend's an idiot.