Basically, you store the screen X and Y co-ordinates of all the waypoints in an array. As the car reaches a waypoint, it heads for the next one and so on.
This is easy in 3D as you just point the car at the next waypoint's X, Y and Z co-ordinates using the Point Object command and use Move Object to set it on it's way.
However in 2D, there are no Point, Rotate or Move commands for sprites so you have to calculate the sprite's direction and movement manually.
I've attached a very rough example I just knocked together to show the basic idea. (Download button bottom right).
Done in a hurry, it's neither optimized nor an example of good coding, but is simple enough to follow what's going on...
TDK_Man
