help needed - mark on dash

[jujututu]

Help! I recently stuck a 3M Go Pro mount on the dash. I've since bought a mount for the windscreen but when I took off the mount, its left behind a mark, darker than the dash itself. I tried a bit of Autoglym Vinyl and Rubber care but its not touched it. Googled it and have read various suggestions - vinegar, 3m adhesive remover, WD40, Goo Gone, Isopropyl Alcohol etc, but I'm afraid to try anything else in case it makes it worse and leaves me with a faded patch. You can't feel any residue so I assume the glue in the pad has reacted with the plastic. The pad was only on the dash for about a week

Any suggestions?

Cheers

Jules