aja8888
Moderator Emeritus
In our Prius I decided not to give in dash navigation and bought a Garmin GPS and stuck it to the windshield. It was a very nice GPS unit. But, it was constantly falling off the windshield which is to say the least distracting while driving. Eventually I gave the Prius to my son and he finally junked the GPS since it wouldn't stay on the windshield. And he didn't like having something on the windshield.
You can get dashboard mounts which I think are preferable to windshield mount but not everyone wants something on the dashboard.
I don't think you can blame the Garmin for the improper or defective mount. My Garmin stays mounted on the windshield 24/7 and it does not fall off on its own. To mount these properly, it's important to have a clean windshield and clean cup surface. I use a wipe cloth with alcohol that I use for my glasses to clean the surfaces. There are also vent mounts that work quite well.
This is my mount with dedicated power wire: