Hi Rocky, You don’t need to remove your bumper it just makes it easier. Check out the video from FD Motorsports. Love the name by the way. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-MRzRKCHeml4.html
I have a 2009 Carrera S PDK. I first replaced the rear muffler with the Sharkwerks cross pipes. The exhaust note was not quite what I wanted….This is my 4th 911. My first was a 1971 T Targa that I purchased in 1973. Modified the exhaust with dual outlets and achieved the perfect, to me and my fellow 911 owners, exhaust note. So, I ordered the Fister exhaust replacements I think this is the exhaust sound I was looking for.