If you have a Garmin GPS navigator, you are most likely mount it with its suction cup onto your car windscreen in order to use it.
The suction cup rubber tend to age and lost its suction power by time, and can cause your GPS navigator to fall off from windscreen while you are driving. 2 years ago, I've posted a solution to prolong the time of possible fall off by reactivate the suction cup power with hot water. Another common method is to make the suction cup wet by putting some water (or saliva!?) onto its base before putting it onto the windscreen.
Now, I found an alternative solution, which is to use Garmin portable friction mount to place the GPS navigator on top of the car dashboard.
This friction mount holds the Garmin GPS on top of the dashboard with strong grip and unlikely to be affected even when sharp cornering or emergency breaking. It has a sticky pliable base which can bend according to the dashboard shape.
After using, you can easily take it off from your dashboard. Although there is sticky material at its bottom, it won't leave any residue on the dashboard.
It's holding arm is foldable to adjust the position of the GPS when use. You can totally fold it down when not in use.