What I wish for is a molded plastic connector, a la Shimano's dynohub connector. It would make wheel changes so much easier for the SON *if* it could accommodate the double wiring I have for the charging system as well as lighting.
I use something like this:
Available from here (but be very careful ordering, or you could be stuck for major carriage costs, possibly import/dumping charges, and sales taxes -- VAT -- on the total value including the carriage):http://www.bmsbattery.com/accessory/439-9pin-waterproof-cable-female-connector-for-motor.html
Seen, with apologies for the photo not being very clear, in my application at:
In which you should note, bottom centre of the photo, that the cable is arranged to enter upwards into the hub below the nut, and to loop downwards before curving back up along the fork. This is by its nature not a very neat installation but it is guaranteed not to conduct water into your hub along the cabling. The cable is permanently attached to the hub, and the waterproof junction you break to take the wheel off is 6-8 inches along the fork, held on above the connector by a tie wrap, and on the lower part by nothing because the cable is stiff enough to be self-supporting. Mine is now arranged to fit behind the fork, out of sight.
Mind you, I've never heard of a SON being damaged by ingress of water, nor the hub I use this arrangement on at the moment, Bafang's QSWXK, but I don't like engineering that is designed to fail, as SON hub junctions can easily be arranged to do, when it is so easy instead to do the job right.