I know if it says Convience Group II then it's definately not the R&T Perf Group. That's a little pointless since if people can see that they'd be able to see whether the Road/Track Performance Group is listed.
The easiest tells are the front seats, and black accented rims. Everything else is also listed under Convience Group II or hidden from plain sight.
Allevon, banned user, said that he had a custom order where he got the R&T without the performance seats and his wheels don't have the black accents. Without a scanned copy of his windowsticker, I guess the only visual cue is to check the airbox, like RTJunkie mentioned.