When I was changing out the window crank mechanism in my door recently, I noticed that the screw heads holding it in place were liberally coated with a white type of goop all around the crank. I've noticed this on other parts cars also, and I'm thinking it must have been done at the Volvo factory at the time of assembly. Does anybody know what the goop was for? Antivibrational?, Anti-loosening?... Should I be thinking about putting new goop on?