I like your solution for the RR mounting bracket, a U bolt. I'll be doing the mod when I get back to Kuala Lumpur.
One suggestion to protect the electrical connections from all the crap thrown up, get some Self Amalgamating Rubber Tape (3M make good product) and wrap up the connector. This tape sticks to itself, you stretch and wrap at the same time. This rubber tape has not adhesive (like electrical tape) and sticks to itself, it forms a watertight protective coating and it amalgamates together and requires to be be cut off.
I use this tape on all my electrical connections that are exposed, clean them first and then wrap. No problems with dirt/water etc again.