Drones don't have to be imported in the track, just edit this textfile to get drones.
Look for the names in data/drones/drones.txt. Then open the track's textfile, and go to "Start of drone paths".
2 // Version
9 // Number of nodes in the track.
// 0: , these are just notes, but write them, so you can find them more easily. (1, 2, 3...)
-3 , 0 , -5 // Position of this node in the world.
DRONECAR1 // Drone which starts to drive from here, or NONE.
0 // (?)
2 // Number of next possible destinations, see note 1.
1, 0,0,0 // Node's identifier (the first number), where drone drives next.
4, 0,0,0 // In this case, it goes either from 0 to 1, or from 0 to 4.
[Now one node is done. Continue with next node]
Note 1: You can set the drone to drive normally from node 1 to node 2, but you can also make the drone to choose their next destination by putting two or more for this value. That's useful in intersections.