I have a 2007 FX4 with the magnaflow dual kit. it sounds great, but may be a bit loud for some peoples liking. i also have the k & n kit, it seems to make a power difference with the exhaust. the magnaflow kit had to be custom bent at an exhaust shop to clear my trailer hitch receiver, and was in no way a "bolt on" kit. the shop also used welded hangers, which really solidified the exhaust.