Mercedes can't stop teasing its super-luxe S-Class Cabriolet

Mercedes-Benz will officially reveal its super-luxury S-Class Cabriolet at the Frankfurt Motor Show next month, but the German automaker can't stop teasing the drop-top beforehand. Following the artist's sketch of the convertible shown off earlier this month, the new image contrasts the upcoming car against its closest predecessor, a soft-top dating back almost four and a half decades. The open-top …