Steering between two Orientations

I'm working on some basic AI for my game with Waypoints placed around the track. I'm needing some advise on the best way using OgreODE to steer between each way point. Is there a way to calculate the ammount of steer needed or a good way of monitoring the orientation of the vehicle as it adjusts it's steering towards a waypoint?

I'm using the Prefab vehicle for this.

I didn't use vehicles before so I can't help but did you just try some factors of the angle?