I'm JK.

I always read the owners manual. If you dont you run the risk of asking a question that is in the first line of the book and looking silly.

Having a manufacturing background I understand some of the silly stuff they say typically is born out the process or testing.
The glass for example. We produced molded vent windows for the STS Seville. You would not believe how hard it is to find something to clean a window that leaves no residual oils or contaminants. We had to ban most of this stuff because it would cause disruption to downstream processes. I can see how that would make its way into the "how to care for your car" Even though the end consumer has no downstream processes to disrupt.