Obviously a muffler delete would be the cheapest route. But I got the Borla S-type axelback and I love it. While it is pricey, it sounds awesome. No drone what so ever and when I step on it, it gets loud. Everyone is gonna claim their exhaust sounds the best to them, including myself, but best thing to do is go through the exhaust thread at all the sound clips, and base ur decision off that. Borla has a comparison of their 3 different catbacks (Touring, s-type, Atak). I figured the axelback would be just a little quieter (which it is, and half the price!). The s-type is the middle ground, it has the best tone out of the 3 IMO. Touring was slightly louder than stock, and Atak was too throaty on the ecoboost, but sounds amazing on the GT.