There must be a seal between the mirror base and the door to prevent damage to the paint. On most Volkswagens, it is a plastic gasket, but on the Volkswagen Vanagon only, it is made of rubber.
If you need to buy a new mirror, this gasket is not always included, check first and order the extra gasket if necessary. Given the age of our Volkswagen classics, transferring your old seal is in most cases not a good solution.
Note for plastic gaskets: Heat the plastic in hot water for a while to make it flexible, so that it does not tear when you tighten your mirror.
Useful information from Paruzzi magazine and from our YouTube channel :
Look for more technical articles on the page Paruzzi Magazine