I just installed my 600 by using the existing two mounting holes where the previous owner had a TT bracket mounted. I made up a small aluminum plate and mounted it to the dash, drilled and tapped for this ball- http://www.rammount.com/CatalogResul...5/Default.aspx
Used a short Ram arm connected to the Garmin power mount for the 600 series- http://www.gpscity.com/garmin-montan...ike-mount.html
This is nice because it hard wires to your electrical system for power supply. You'll also need to but the ball for the back of this mount. Look on the Rammount.com site or call them and let them know what part you're looking for.
Pretty clean set up and way cheaper than TT's system
Sorry but I don't have any photo's of the set up.