That is so ghetto fab
Seriously 4" resonator Magnaflow, and if you want one of the most quiet performance mufflers I have ever seen, grab a Borla catback with the stainless "intercooled round exhaust tip". I have nearly identical setups on two cars until you get to the muffler, one with the Borla is significantly quieter. The tip you put on will make a difference. It's like the end of a trumpet, change the tip size and shape, it will sound different. A good resonator is a must to cancel harsh chainsaw frequency sounds. 4" with 2.5 inlet/outlet pipes cancel out most of the nasty sound.
VERY Quiet: Borla exhaust w/Magna resonator, HFC. Car almost looks less evil:
Less quiet but ok below WOT: Custom Magna with HFC and bigger DP/Header, too:
"Crap I ordered the 4" DIAMETER tip not 4" long and man is this loud (but not raspy) under WOT" - I don't recommend this if you're trying to fly under the radar - it rumbles under normal use then reminds of half a 1960's Muscle car V8 under WOT - loud, but not nasty loud. VRS 2.5 or 2.75" cat-back stainless with Magna resonator and perf-core muffler:
All 3 use magnaflow HFC's, resonators, and mufflers. Pretty much the same resonator: