I went with a semi-bastardized Powerlet solution - got one short Zumo-Powerlet cable (http://www.powerletproducts.com/product/garmin-zumo-short-powerlet-cable/265) and one short Powerlet-cigarette lighter adapter cable (http://www.powerletproducts.com/product/cigarette-plug-to-powerlet-socket-cable/3). Works like a champ, no splicing necessary.
I had a Kury fuel-door mount on my '07, but it won't fit on the new '09 RG. I had a bunch of RAM parts laying around, so I drilled and screwed in a RAM ball on the stock fuel door. Works just as well as the Kury mount, plus gives me more options for viewing angle, height, etc, and didn't cost nothin' extra.
Best part of all this setup is it can be completely removed without tools if desired, just leaves behind the RAM ball.