I forget exactly what minor mods have to be done and I have not done it myself but I've seen them installed and the owners say it was not bad at all. It is a great option for a lowered car that is having trouble with the over axle tubes on the traditional catback and it honestly looks sick out back especially if you have one installed that is polished up to a mirror finish
edit: The Google she knows much
Try Google first next time, I got the link to that thread from a Google search in under 30 seconds.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.