Cat-Back vs. Rear Section

A cat-back is a half-system that bolts onto the cat but someone claimed they invented the term and they had to be called something else. The 2005 Mustang exhaust is pretty unrestricted until you each the back boxes so it made no sense to pay for the bit you didn't need to replace. The stock system is good on power too so the aftermarket rear boxes add no more than about 7hp on average and it's a noise thing you end up paying for.

Needless to say, the manufacturers spotted that they could make more money by selling the centre section separately and so offer X pipes to replace the stock H-pipe.

Can't help on the stingers but the Corsas will be too quiet for you as I took mine off for that reason. Plenty of exhaust threads on here. IMCO and Violators spring to mind as recent recommendations.

Yeah, don't waste money on the mid pipes as the stock ones are 2-1/2'' mandrel bent stainless already.