When I had a Skoda Octavia on the scheme I had the same problem. My solution was to pay the dealer to do a modification in the fuse box so that the USB ports were only live when the ignition was on. I believe this basically entailed them fitting a short piece of cable between 2 sections, very minor. I paid because I worried if I did it myself and the car went up in flames, I might have a problem 😂. This mod was listed on the actual invoice so I was covered. I think I paid around £85 but decided this was worth it for piece of mind in case of any consequent issue or flat battery.
