A picture is worth 1000 words…
I’ve tried three or four of these stick on the windshield holders. The ones I’ve seen, the suction pads actually have a sticky surface, which helps them hold much better than a plain suction cup. But my experience is also that they are good for two or three times taking them on and off, and then it’s almost impossible to get them to hold. On this one, I mounted it so that the arm actually barely touches the top of the dash pad, and I put a tiny drop of E 6000/goop right there. It seems to be solid as a rock.
Each design seems to have a different annoying quirk. The issue with this one is that the width of each of the jaws that holds the phone are not deep enough. So when you clip your phone in there, you have to do it just right, or when you hit a bump, the phone will fall.
The one I have in the Road Ranger has a similar suction cup, but then a flexible arm like an old desk lamp. The clip is similar to the plastic curved hair clips that the women use to pull their hair up out of the way when they’re doing something. Those clamps have a soft rubber tab inside them that really holds the phone great. But with the bendable arm, the phone is shaking so much back-and-forth and up and down that you can’t tell what the hell is on the phone in the first place. I’m probably going to fabricate some kind of a little T shape thing that I can glue to the dashboard with a saddle on top that I can goop to the flexible arm.
Which brings me to another helpful hint. When I need some peculiar thing like that, I no longer try to build it from scratch. I learned a long time ago to go down to the Goodwill, and go to the toy section, and find find a toy in the right color where that shape is part of the shape of the toy, and then just cut it out with a hacksaw. With a tiny bit of cleaning up, it looks like it’s made for whatever you’re using it for.
I actually have a box of broken up toys and plastic pieces from whatever that is my go to when I need to fabricate something like that.