Stunt Race FX? If I recall correctly, the Super FX Chip (which was also used in Star Fox, the unreleased Star Fox 2, Yoshi's Island, and I BELIEVE Super Mario RPG) was originally called the Mario graphics chip. So it's not so much a cameo as it is the original codename of the special chip. Nice find, though! I guess the developers grew attached to the old name or something and hid this text in a line of code.