[mrchen]

I took my 2013 LFX in today and got dual inlet outlet Flowmaster super 40 installed.
I added the DEI tunnel shield heat shield and sound absorber over the factory resonator tunnel material.
We cut out the h pipe and mounted the muffler all the way forward, right after the pipes turn straight off the converters.
It fits very well. Then add h pipe after and we ran new custom 2.5 inch plumbing out with stock tips added. The heat shield fit back on and has one inch clearance with four washers under each bolt. No rattles and more clearance.
Wails like a GTR when run hard, dead quiet but nicer when just putting around.
I'll shoot some vids later, it's gonna rain. Sound inside is nothing until yu roll window down.
100 percent success, cat back systems suck, they sound like shit and cost way too much. My system is just under 400.