Recommending Borla or Magnaflow is fine, but the sound quality has a lot more to do with the
type of muffler, rather than who manufactured it. Borla and Magnaflow both make high quality mufflers. Edelbrock RPM Stainless mufflers used to be some of the best out there, but they were discontinued in 2007, damn shame too.
I have a lot of experience getting good exhaust sound out of a Taurus SHO Yamaha V6, so the exercise with the V6 Contour is rather similar. In the time I've owned my SHO (since 1989), I've had about 5 exhaust systems on it.
If you're doing a 2 >1 >2 system, you DO want a center resonator, if you delete this component, you will get the dreaded rasp or buzz, which is the high pitched noise you want to avoid.
Avoid chambered or "turbo" mufflers like the plague, these will give you rasp. You want a center resonator and mufflers with perforated cores and packing around the cores. Fiberglass packing is cheap, think old fashioned Glasspacks, and it won't last long. Refractory glass wool packing is better and will last longer, Stainless steel wool packing is the best, it lasts damn near forever, but costs more. Borla makes unquestioningly the best perforated core, Stainless steel wool packed mufflers on the Planet, and that's what you're paying for with Borla.
This is the best Taurus SHO exhaust system I ever made. 3" mandrel bends from cats to tailpipe, great big Borla XR-1 race muffler as a forward resonator, and a large oval case perforated core packed muffler at the rear. It sounds positively awesome, it has a low rumble at light throttle, and when I get on it, it emits an evil low roar that turns people's heads. The right mufflers gets the right sound. The engine is a 3.2L low compression mill with a Vortech supercharger.
,,, I have an empty main cat factory resonator back to a 2.5" Y and resonated tips.No mufflers are the best mufflers