I've completed my trailer script. Now a truck can transport the artillery-canon!
The direction of the trailer is adjusted correctly depending on the trailing vehicle's direction -driving backwards is awful (ever driven a military truck + power generator? )
But: For trailer positioning I use the "SetPos" command. As a result, the trailer's aligned horizontal -that looks very weird on steep hills!
How can I "setpos" the trailer parallel to the ground it's standing on? Is there any other command like SetDir?