Most likely there was a cover. I have the same problem with my 560SL. These things get removed and discarded because they are considered a pain in the butt. For my car the pannel swings down and requires a lift to get enough clearance to swing it down. Therefore they are commonly removed by owneres who do there own oil changes or just discarded if they get damaged. Todays MB's recomend removal of old oil with an vacume extractor through the dipstick tube and at the time I left the dealer the new engines were coming out with filters on top. This eliminates the need to ever remove the cover. I will probably get a new cover and deal with it during my oil changes. Does any one have an approximate price on one of these covers for a 560SL

John Roncallo