Congrats on the Toyo - nice buy!
Go the Hayman Reece hitch - as someone pointed out, they are the factory unit! (Try the wreckers - cars been out for a while)
The module would be to hook the trailer up to the cars wiring loom / or if you have bulb failure detection - It will go nuts with the extra load!
Shop around - my contact is in Vic which is of no use to you - sorry!
The 1200/1600kg jobs I would fit myself - the 2300kg+ units - some bolt up - some need a fair bit of modification to fit...
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MARTY: I noticed you have a terri too! Will a machine fit in the back with the headbox folded down? (Or anybody else who has a territory?) Mines a 5 seater...