I am feeling quite smug and sheepish at the same time, as the perfect solution was under my nose the whole time, since I always use a regulation hockey puck as a cushion when using a jack under the car. I was getting a little tired of testing my reflexes by catching the Garmin whenever I accelerated.
It turns out that a brand new, regulation size 6 oz. disc of vulcanized rubber (used to play the only worthwhile sport outside of motor racing) is a perfect fit in the center dash drink holder. The puck is a perfect fit, since it allows the drink holder to be pushed in enough for the base arm to retract upwards, leaving enough room to still load CD's into the 6 disc changer (factory stereo) Garmin's suction cup grabs the biscuit firmly providing a nice platform.
I tried a $5.00 candle in a jar (from target) with a little padding around it, which sat nicely in the holder, but needed some extra shimming to prevent rotating. Then, after a few ounces of Junior Johnson's Midnight Moon 80 proof corn distillate, it dawned on me that the perfect diameter (and depth) disc for the job was already commonly manufactured. Ka-frickin'-Pow !! Game on !Laugh!
Sorry to not post pics, you'll have to try it for yourself
The beauty is that the nav sits below the windshield, but close enough to touch and the only thing sacrificed is one dash vent which is usually blowing too much cold or hot at my passenger.
BTW, the nuvi1300 already was acting up, so I traded it in on the replacement model with Best Buy (forgot the number) Back to my adult beverage