Justin: All of my 1986+ cars have done that. I don't remember if the earlier ones do or not, but it's normal.
2003 S500 Black/Charcoal
1990 560SEL 61k Arctic White/Grey
1988 420SEL Black/Palomino Sold @ 85k
1987 420SEL Midnight Blue/Grey
1986 420SEL Diamond Blue/Grey
1983 380SEL Champagne/Palomino