Always wondered what an active exhaust muffler on a fox would be like.Factory 2011-14 GT muffler look like they would work, 2.5" inlet/outlet from what I'm seeing online.
Way too pricey to try out though
https://www.americanmuscle.com/roush-active-exhaust-1516gt.html?utm_content=Exhaust - Axleback|Roush&T5_Var4=389790-B&utm_source=google-pla&utm_medium=shopping&T5_Var2=shopping&utm_campaign=AMM+Mustang+Vehicle+Medium+RLSA&T5_Var3=blue&intl=0&dialogtech=ppc&gclid=EAIaIQobChMIht3rkPDh4gIVWYezCh2OsQw2EAQYASABEgKUcPD_BwE&gclsrc=aw.ds
HOA's are hit or miss. I lived under one, and it had it's bad with the good. The politics were what burned my ass more as some people got a long leash, and others got dinged with every little thing depending on who was bingo buddies with who. I don't live in one now, but live in a pretty nice neighborhood with a lot of good people that i respect, so i can see trying to somewhat be courteous to others. I usually try to not start the car too early or too late and for the most part, i idle in and out of the neighborhood. Lots of young kids around too.