May be just the old geezer in me but it seems like that mod may look nice but would be expensive, possibly affect performance and definitely would cost you the loss of towing ability and spare tire storage.....
What would you do if you ever wanted to tow something?
What would you do if you ever have a flat tire?
Where would you store the spare tire? Loosing bed storage or put it on a roof rack? Or just cross your fingers and hope you never have a flat tire? Are you the only driver or would a wife or child be driving the AV too and they could get stranded?
Again the old geezer in me would say "why try and reinvent the wheel?" when plenty of exhaust companies have already done the fitting, performance testing, and other things to market a good quality warranted CAT back system such as CORSA or Magnaflow.....with them you get lifetime warranty, good sound and great performance. You also keep your ability to change a tire in an emergency or tow something.