Joe I'm not sure if you still need the help, but I can help because I installed the S281 wing on my yellow "03 convertible. You do not need to do any additional drilling and you need to mount the side pieces with 3M tape.
If you want it loud like your Roush you will need the Borla Stingers as mentioned or the Magnaflow Magnapacks. The side exit from Roush is better than stock but still very tame.