On a Mercedes SL280 1994 should the door window open slightly when you open the door?

Yes, on a 1994 Mercedes SL280, the door window should open slightly when you open the door. This feature is part of the car's design to prevent the window from getting stuck against the weather stripping and to maintain a proper seal when the door is closed. If the window does not move, there may be an issue with the window regulator or the door's electronic control system.