Should just be a matter of parking the buggie in front of the trailer so that the joints are semi-near eachother, then get out of the buggie, and left click on the trailer and it should auto connect. If that doesn't work let me know.
I'm having the same issue, but I tried your suggestion and it's still not working. I'd love an auto connect within a large area so I don't have to line it up or question if I need to be lined up right!
