new portable device dash mount tech

For mounting gps units, cell phones, tablet pc's etc. an interesting type of compact dash mounting has been introduced by Bracketron they call MobileDock. The advance is that this is a "diskless" suction mount that grips rough surfaces via gel type material in the base seal, preserving the dash from any permanent modification with glue. It works on the deeply grooved Prius dash.
Unlike everything else I've seen that attempts to mount stuff on the dash without damage, it sticks tight like a windshield suction mount. Some of the other means of mounting such as vent clips don't work on the Prius center vent with a very thick, single blade and narrow slot etc.

The device also eliminates all the device specific brackets, so-called "holders", with more chemical trickery, a tacky disk which holds anything on it's universal cradle while removable anytime.

Beware that an initial design was sold to distributors which is not as good as the final design being sold, and may be found heavily discounted. The photos online at dealers (instead of mfg) of these may also be of the new model, except for the packaging which might show what is actually supplied -- an unfortunate situation (they just used stock photos from the mfg one suspects). The new design has a curving arm with a ball joint, lacking on the earlier. The initial design did not allow the cradle to position the device vertically, and had more limited range of motion. To use this with a Garmin GPS I found it useful to screw the joint ball from a Garmin mount onto the center of the tack disk, so that more range of motion could be had.
The new model should not require a Garmin holder at all. It does use a ball joint like the Garmin, however, but about 1/32 smaller in diameter. A bit of tape would probably make this fit the socket on a Garmin holder, should that be preferred.

One of the advantages of portable devices over built-in vehicle equipment is that tech advances can be used with new stuff as it comes out over years, and the rate of change is quite high. This applies more to digital data devices, computer related, than to things like audio, with lots of parts like speakers and so on, best built into the car.