I have corsa on my 2011 convertible. It is absolutely drone free. You can here when you get on the gas and not at all while cruising. I love mine for my convertible.
I had a GM Performance Parts axle back and that didn't drone. Bit overpriced if you buy them from a GM dealer though.
Other than that, has anyone else heard the following reputable brands?
The flowmasters aren't pretty ... but they have big mufflers so you'd think they'd be less like to drone.
I know Borla say on their website they don't ... But I'm not a fan of the 6 cyl system ... a bit too "raspy" for me.
I read an article somewhere recently where someone trialled all of the known brands of aftermarket exhausts on a mustang ... and in that case the magnaflow had the lowest spl.
782.5rwhp 680 rwtq 2011 Inferno Orange 2SS, STRUT 22" Icon5 Rims & Grille Kit, Mahle Pistons, Manley Rods, Custom Comp Cam, ARP Bolts, Melling HV Oil Pump, Whipple SC, 3.5" Pulley, 8 Rib Pulley Kit, Innovators West 10% Overdrive Balancer, LT Headers, Borla 3" Exhaust, ADM Fuel Pump, 80lb/hr FIC Billet Tip Injectors, RX Monster Catch Can, CAI Intake, ADM Race Scoop, Mantic 9000 Series Clutch, Hurst Shifter, Eibach Springs. Motor built by PFAFF Engines. Fitted & tuned by Cunningham Motorsports.