Autodrive is rather primitive. With the Remote control, you can select one or more vehicles and send them to a destination, but you can't define a group of waypoints. If you want to define a path by just marking a number of positions on the map, you should use AAI Programmable Vehicles.
However, there is a Circuit network sensor that lets vehicles react to circuit network signals transmitted with the Shortwave mod (it's already a dependency, so you should have it). It's not easy and requires several combinators per waypoint. Somewhere in this thread I've discussed route programming with dorfl. I've made a basic prototype that worked, but it wasn't really useful because I didn't have bot researched at that time, so vehicles couldn't be used to automatically transport items between different positions. It should have worked for sending some vehicle on patrol around the base.
Also, my design used about a dozen combinators per waypoint and vehicle (I guess somebody like DaveMcW would be able to make it more effective, but he plays in another league). So setting up several routes with a lot of waypoints for even a medium fleet of car-like vehicles will require some space, time, and patience. :-)