The 1:43-scale is also an S500 but made by Schuco, and features all the optional (scaled version) amenities that the fullsize S-Class can brag with, like a panoramic sliding roof, a LED Intelligent Light System and the First-Class rear suite with Individual Entertainment system.
The smallest one, in 1:87 scale is built by Herpa and is also pretty detailed, comprising of more than 26 individual parts.
The 1:18 scale can be bought in Germany for 79.90 Euros, while the 1:43 and 1:87 can be had for 29.90 and 15.90 Euros, respectively.
The miniatures are part of the Mercedes-Benz Collection and are available exclusively through Mercedes sales and service outlets and, of course, dealerships. The Mercedes Museum in Stuttgart and the online shop haven't been forgotten, especially since those will probably be the outlets that will have the best sales.