bertrandtech.ca/bgeigienano/index.html
The pad is cut from a
kneeling pad for gardeners, keeping the soft side toward the car to minimize scratching the paint. Cut two slits for the straps.
The straps are just 3/4" (19mm) or 1" (25mm) wide nylon straps (black is best to minimize weakening due to exposure to sunlight).
The Velcro is sewn on the ends.
The straps are inserted into the slits, looped around the case handles and under the unit (across the front). You need to loosen the
straps a bit to open the case to turn it on or plug in the charger.

Let straps dangle across the top of the door frame, ready to be trapped when the door is closed.
Oh by the way, did you turn it on? The metal toggle switch should be in the down position for logging,
the red LED should be on solid, and you should see the CPM value and the time and altitude in the display.

Close the door, trapping the straps between the door and the top of the frame.

Now the straps are dangling inside, ready to be pulled tight.

Pull the straps tight so that the Nano and the protective pad are firmly attached to the car. The unit should not flop around (it's gonna get windy!).
Wrap the straps around the "Oh s**T" handles for nervous passengers, and fasten them with the Velcro.

Ready to log radiation data! Measure the height above ground (meters) and record it
as well as the direction the Nano is facing (in this case, approx. 1.6m facing right)
(Did you remember to turn it on before mounting?)

Another view of the mount.
(You turned it on, right?)