Re: 99-04 v6 true duals (help!)
Technically yes, because they eliminate the catalytic converters which are mandatory by most states for emissions. That's usually why they call them "off road", because they are intended for vehicles on the track. I'd check before getting one, you wouldn't want to get burned for not have cats on the car.
A lot of people use them though...I don't think you'd have to worry about violating noise ordinances too much with a v6, it will sound raspy and high pitched, which makes the v6 sound nasty. An 03/04 cobra is a different story though, I'm sure you'll piss a multitude of people off with an o/r pipe of any kind.
12 Black GT500 SVT PP l 2.6 Pulley/Idler l Airaid l o/r X l 305 NT555R's l Recaros l
04 Azure Blue Mach 1 / 03 Sonic Blue 3.8 / 14 Sterling Grey F150 FX4 402A 5.0 / 11 GT500 R.I.P.