I am having WO 578 bars installed on Wed 1/20 at the dealer, normally do them myself but it's free labor part of the deal to buy the '16. I posted a thread earlier about wiring these and a forum member named Basscat said he put those on his and had no issues.
If you would, keep me posted on the outcome. All of the pics that I've been able to find, it looks like the reverse wires are external. But, now that I think about it, the Rushmore's use a different switch set up, don't they?