I have a complete MBRP 3" cat back with x-pipe that I took off my 2015 GT. It was too loud for me (yes I am aware that makes me old.) I would be willing to let it go cheap. No idea what shipping would cost.
Mine had the MBRP 3" street catback with the H-pipe when I got it. Too loud for me (I know, I'm old) so I switched to a Ford Perf by Borla Touring 2.5" with X-pipe. Less drone below 2000 rpm and not as loud. Definitely more of a raspy sound, the H-pipe had more of a muscle car sound...
I recently replaced the OEM clutch in my 2015 GT with a RAM clutch and flywheel. Much stiffer feel and better bite then the OEM one. This was at 80,000 mi, when I bought it at 30,000 mi it was already on it's 2nd OEM clutch. The friction material on the one I removed was fine, a damper spring...
It might not be recognizing the key fob. Does it lock/unlock the doors? Pull up the rubber mat in the bottom of the cupholder, the rear one has a slot to put the key in if the remote battery is dead. Try the other key fob if you have it.
If the steering wheel is "locked" because it was turned when shut off, you may need to "unlock" it by unloading it (i.e. turning it the same direction a little more) then press the start/stop button. I seem to remember something weird like that happening to me once.
I will say this about noise. The MBRP 3" street exhaust with an H pipe did have more of a muscle car sound. I take long trips and got sick of the loud drone.
I just put the Ford Performance Touring cat back exhaust with x-pipe on my 2015 GT. Much quieter than the 3" MBRP with H pipe that came on it. I noticed less drone with the x-pipe, and it does sound a little like the GT350 when running it up thru the gears. It is a little raspy on cold start...
I have the LMR SVE350R in 19x10 +35 square with Michelin Pilot Sport 4S 285/35R19 for summer. Dramatic improvement in the handling and appearance, fitment is perfect (clears the Brembos.) I kept the stock wheels with Continental DWS06 for colder weather. I need to get some splash guards like...