Now i'm working at car AI with physX engine, and have some first results!
I never seen px car AI at AUM or at the forum and i'm glad to share it with you guys

AI drive thru the path and randomly turns on crossroads and stops near trafficlights and other cars (red debug vector and text)
also it slowdown near sharp turns (angle of turn calculate using next 4 path nodes (blue debug vector))

To get smooth steering i calculate bezier curve from car.x, node1 and node2 vectors (green debug vector)

Car models i made by myshelf (it is my first models!) using papercraft textures from this site eek laugh

You can check my project on GitHub!

[Linked Image]
[Linked Image]