My first aftermarket muffler had the same crappy fit. It was a Stebro Sport Exhaust. I was able to improve the fit by loosening everything, forcing the system into a better position, and retightening the fasteners.
I wonder if it is a coincidence that these mufflers both fit so badly in the same fashion?
At first I was thrilled with the sound. After a couple of years, I grew to hate the drone; especially when running with the hardtop on and even with the soft top up. I was never happy with the fit, but it was the drone that led me to get rid of the Stebro.
I replaced it with a complete NHP system which was terrific. No annoying drone whatsoever.
Before and after pics of the Stebro after the adjustment.
