I gotta say, even though I like the sound and I got it for a screaming deal, the more I work with my 3" dual exhaust on the Nova the more I just shake my head at how much it's a PITA and not necessary. The clearance is not that great, I had to heat and hammer the pipes to get it to clear the tires, and it's pretty heavy.
So nut up. What have you guys bought that you wish you hadn't?