Great contribution!
What about
Rubbers?
I understand that Lanolin has a restorative effect, also coating with talcolm powder is good (for parts that seal moving surfaces like doors)
Felt-finish window guide rubbers- is it good to use spray silicone on them if they get sticky? Or is the only real way to replace, or remove them from the door (carefully) wash with soapy water, rinse and re-install?
Seat belts when they don't roll up? Silicone spray?