An easy fix is to use an old bike innertube and cut to size. One inntertube can create many times of gaskets and seals when needed. The other fix is the rear view mirror pad for the car windscreen https://www.ebay.co.uk/itm/2X-ADHES...815386?hash=item4b5eba4eda:g:lRQAAOSwxYxUyPrg It has a double sided adhesive either side of a small foam pad but you can leave one sides vinyl on to help
thats what i have been using on my bike for a while now bolted to one of my mounts www.iconicparts.uk
Got this quadlock mount for my PP from evotech the other week, took ten minutes to install. Seems solid so far. I use Waze for satnav and the Spotify integration let’s me list to music neatly.