This is Mercedes-Benz S600 Coupe of 2000 year. I know there is SL50 that looks the same. I wish I knew all the models that are associated with this and look the same.
That's a Mercedes Benz C140 body, the coupe-version of the S-class w140 limo. For a list of the models, i.e different engines, that was made; take a look here: http://en.wikipedia.org/wiki/Mercedes-Benz_W140