I swear I'm like the only modded MK6 GTI in Foxboro! Heck, I think I have the only MK6 GTI in this town lol. However, I do not have either mentioned catbacks on my car.
There's a guy on Vortex that had a Borla Cat-back on his 2-door OBP in Bellingham/Franklin area. I used to run into him all the time over by BJs right off 495.... Haven't seen him in a while though. Maybe check on that forum if you're still looking to hear it up close.