My first mustang a 98GT didn't have any paperwork, not even a manual or a second key. The previous owner stripped it before trading it in. The roush though had tons of paperwork and documents, window stickers and books. I definitely like having all the paperwork.
2003 Roush Mustang GT Stage 2 Package - Current 'Stang
1998 Mustang GT - Previous 'Stang