I used the mini Techmount http://www.techmounts.com/products/in combination with a mounting plate and power cable from the HD handle bar mount part #92321-06. That gave me a clean GPSinstall on the lower part of the handlebars with both power and audio capabilities through the AUX plug on the radio. When I park the bike the GPS is easily removed for secure storage or cleaning. https://www.hdforums.com/m_3017042/tm.htm
Mine is simple-- Garmin Nuvi 765 plugged into the cig lighter and mounted with the original suction mount onto the tach face. If oyu mount it right you can see the tach needle sweep good enough (if you need to see it).
I use the FM transmitter in the Nuvi for sounds so only 1 wire and it's EZ on-EZ off.
tpmurray, that really is very neat! I don't like those Ram mounts and went out of my way to find a tidy installation off my bars, but that one of yours deserves a prize.