...posted a bunch of racing games still PPC compatible recently on his blog. He has a G4 500mhz Sawtooth with a decent videocard, so you may not have the same results. Some of these games are free. Google is your friend.
Driver this is the funest driveing game ever!! it only runs in classic mode
it is super hard to find a mac version of the game cd i don't have the cd any more because i sat on it (forgot it was on my bed). now it is only in my Lime g3 imac (i think any way?) but it is so fun i will have to get my imac out and play it!!