I haven't tried them on a 6 (yet) but I have good luck with (and like) the Dynomax super turbo mufflers. I have a set on my A (bent 8, bear with me).
It's cammed up enough (with some compression and a dearth of flywheel mass) that it has some lope at idle, nice melow sound (unoffensively quiet too). It doesn't get 'loud' till you are 2/3 throttle and above (it's still not
that loud, and by that point sound would be the least of your concerns with the Po-lice
).
Not sure how that would work with a sigle piped 6, or even a split exhaust W/ twice pipes, but they were cheaper than either Magnaflow or Borla and have stood up to a beating, literally.
