There was an article in CPA magazine with a full description of a Roady installation last year. It gives the part # and supplier of an adapter which I bought for approx $40. Alternately, it also tells how to modify the 12 VDC cigarette lighter plug which comes with the Roady. I also did that with $3 in parts from Radio shack...but you gotta be pretty good with a soldering iron. If you are a CPA member you should be able to go to their web page (
www.cessna.org) and find that old issue and article. If you aren't a member email me and I will see if I can find a copy of my old instructions.
I installed a cigarette lighter aux recepticle from my fuse panel (with the work signed off by my mechanic in the log books) and plug the modified power plug into it. That makes the Roady a "temporary" installation so it doesn't have to be signed off.
Plug into your audio panel, throw the antenna on the glare shield and enjoy. I have no interference with my GPS430 or portable GPS295 with its antenna right beside the Roady antenna. Mine has worked great for a year!
If you want to discuss just call me at 864-419-9934.
Hope this helps