It was a squeeze! I don't know how other people have done it but I found cable-tying the adapter under the ignitions switch mount works well, and taking the negative from the frame definitely helps :smile2:
I just bought the hella to trumpet optimate adapter and plug it into the aux socket, dealer didnt want to fit the optimate lead to the battery as it was a tight squeeze with all the other crapola i have hanging off it
Motorcycle of Dulles (MOD) here in Northern Va fitted one for free, so was on there when I picked it up. They do it as a courtesy for all their bikes. I may relocate it though as it's zip tied to the frame.