I bought a bracket on ebay which clips into car vent slots - fits most types of car it said - but not my car, a clapped out Vaxhaul Astra. So then I discovered that they do "Bean Bag Dashboard Mounts". It's a bean bag, with a bit of plastic attached, and they want... 25 quid for it. HOW MUCH? I'm not paying that! (Well belatedly I discover that there are unbranded copies available for half that. Too late now..)
So I made one for free. Yes, genuinely, all parts and materials were things I had around the house.
I used: The original suction cup and connector, an old Wallace and Gromit sock (any old sock would have done, but Wallace and Gromit seemed appropriate for an Instructable); duct tape (some chaps who did a fencing job for me left it behind, they charged me a king's ransom, so I did not feel too guilty about the gain); a piece of hardboard (the white kite shape on it in the image is the legacy of a previous use, and before that it was probably a picture frame backing); wood glue (strong PVA); a piece of non-slip matting (it was left over from a length I bought to sit under a scroll saw); a handful of gravel (from the greenhouse for top dressing potted plants); a piece of plastic coated garden wire.