Yes. There was a limited edition S500 for the '99 model year. It was called a "grand edition" and had the AMG style wheels, two-tone interior like the S600, and several other things that the S600 had - not sure exactly what. I am sure someone can chime in on that.
Basically, the S500 Grand Edition was the predecessor to the designo package with exterior in obsidian black and the interior in charcoal and gray.
I am thinking they limited the run to 500 cars and was only available to the North American market.