After thinking of the best way to mount my phone sturdy enough to take images while moving in the car I came up with this with parts from a sports camera and a selfie stick.
These parts are sold online cheap so anyone can make this mount and it does not cost much.
You will need the following:
* One glass suction mount typically used for sports cameras.
* One bracket that holds a phone. These are typically used for selfie sticks/monopods.
You will also need two cable ties, pliers (optional) and wire snips or scissors.
Join the two by screwing the bracket onto the suction cap mount. The thread is the standard 1/4-20 UNC used on most photography equipment.
It is up to you which way you want the glass mount to be as you can have it so the phone is forward and lower or back and higher depending on where you want to mount it in your vehicle and what obstacles (rear view mirror) or obstructions (drivers view) it may cause.
Be sure not to screw the phone bracket in too much otherwise the bracket may break or the thread assembly to pop out of the bracket plastic.
To strengthen and stabilise the phone bracket use two cable ties to hold the bracket to the suction mount even more. This can prevent wobble and sway of the mount bracket.
Tighten the cable ties with pliers and cut the excess off.
Left: Forward and low mount - the one I made just now you see in the images above.
Right: Back and high mount - original one I made and have been using.
Basically you are merging what mounts best to glass to what holds a phone best.
With the mount in a vertical setup this has less strain than mounts that reach out to the side or forwards which can wobble too much.
This example is with a Samsung Galaxy S5 in a OtterBox (rubber inner, hard plastic outer).
Long term there isn't much maintenance except for occasionally tightening the glass mount clamps as they can loosen from vibration but this is not very often.
The phone bracket spring that pulls to clamp the phone will stretch over time but again this is not a big issue. You may get a year or two out of it but to replace it is really cheap online.
I hope this helps in finding a cheap solution for everybody.