Hello, looking for some help regarding the fitment of my future setup and what I am trying to do. Currently, I have a CTS turbo 3" catted downpipe to the stock res and then a muffler delete on the stock catback. Obviously, this is way too loud. I've been reading this forum and I think that I am going to go with either the 17930 or 17950 depending on fitment and a Borla XSPro muffler. My question is if I should get the 17930 or the 17950 if I have a 3" downpipe but am planning to continue onto the 2.5" stock catback piping after the res. My next question is regarding which Borla XSPro muffler I should get if I want to place it under my fuel tank in that bend. Offset or Inline? Help would be greatly appreciated. Thanks.