A demo / build I kinda want to see discovered is this:
I'm guessing there probably won't be very much interesting stuff in there, but from the footage alone, it's still not exactly like the final.
The music in the races is what gets me. The Smokey Mountain race has Lenny Kravitz playing in the background. Lenny Kravitz was only featured in the NTSC-U version of GT3 if I'm not mistaken. While the description of this build in the demo disc states it as "the import version of the game", so the build is likely Japanese.
Same thing with the first race on Tokyo R246. I have no idea what that song was, but I'm pretty sure that doesn't play in the NTSC-J version either...