What you hear is noise coming out the back of the muffler... Imagine sitting behind it in another car and hearing that. Insulating your own car would be way too difficult as it all boils down to reducing the volume of noise from the muffler exit.


The borla system works perfectly at reducing that 2000 RPM drone in top gears, It uses 2 full size free flowing mufflers...

I would install a larger resonator, or even a 2 chamber resonator (muffler).

good luck.