"Before diving in, I looked at the new HD clutch mounting kit, and it looks pretty clean, but my parts guy said it would only work with the HD version of the 660, not the Garmin version...??? WTF is up with that? So didn't even try it, plus my 660 cradle would be hanging on my bars all the time."
BS. I bought a zumo 660 on sale for $599CDN from a local GPS/Ham radio store in Toronto - Radioworld - and after deciding the supplied h/w would not do, I went to my local HD dealer and bought the handlebar mount kit (p/n 92378-09) after seeing it installed on an EG Std. Worked flawlessly on my '07 Ultra. After checking volts and amps with a multimeter, I spliced the 660's power wire into the hot lead off the cigarette lighter to make the electrical connection easier. A little playing with the position of the unit and I can still see the gas gague pretty well.... my $0.02 worth....
Milkbone
Stouffville, Ontario, Canada