Attach a vehicle to another vehicle as a trailer.
|trailerid||The ID of the vehicle that will be pulled.|
|vehicleid||The ID of the vehicle that will pull the trailer.|
This function always returns 1, even if neither of the vehicle IDs passed are valid.
new vehicleId = CreateVehicle(...);
new trailerId = CreateVehicle(...);
This will only work if both vehicles are streamed in for a player (check IsVehicleStreamedIn).