AI doesn't know when to use the reverse gear

[fudje]

It would probably be sensible to instruct the AI to employ reverse and appropriate whenever it is stopped and the direction of the nearest point on the course is more that 3 * M_PI / 4 (135°) from the direction the vehicle is facing.

But there's a lot of work needs doing to the AI. Most of what it does seems from observation to be guess work, so many cars fail to even turn corners properly (M7 is an example of this behaviour IIRC). Also, there is no collision avoidance. These are not trivial tasks by any means.