Quote, originally posted by just4fun » The seals are still supple, but they have the "cat tongue" feel to them again.
I think you identified the key criteria, which is that the seals are soft, supple, yielding, and will conform around the top of the windows when the windows are lifted up.
When seals are dry, they are firm and resist deformation. I don't think visual appearance (shiny, etc.) is significant.