I have the entire "S" catback with X and it is best exhaust I have heard on these Coyotes. Now if you go Catless that's a whole other nightmare and will turn it to **** for sound.
2012 Prem. w/ GB insert stripe/stitch , M6,Brembo, 3.73,Stock Air-Box,93-R Tune,Borla Catback w/ X-Pipe,FRPP-"K" Springs,BMR PH Bar,BMR Upper support brace,BMR Reloc. Brackets,CHE Lca's, Koni Struts/Shocks, Jlt cc,Saleen grill, Hydrocarbon Center console/stereo surround,Formula One Tint, MGW w/ speedawg ball match seat inserts,SOS Dual Aeroforce Guages,MT82 Amsoil MTF.METCO Uca/Ucm, Shaftmasters DS