If this works it will be the best thing since sliced bread, I hate having to remember to switch it on before I get going. Probably the single most irritating thing about the Navi system.
There has been a lot of discussion about the black and white wire on other forums, and last I checked nobody could make it work consistently.
I had been told (and this may be Honda doublespeak) that the VS sensor hookup was only for situations when the GPS had no satellites. When the GPS is locked on to satellites it makes its own judgement about vehicle motion and prohibits operation if moving.
I really hope someone tries this and can verify that it works, I would do it myself, but with 3" snow and -10C I wouldn't be able to test it until next spring.