New and used Mercedes S550s are available for sale across the United States at Mercedes-Benz dealerships and online at CarGurus.com and Autotrader.com, as of 2015. Both Autotrader and CarGurus allow users to sort listings based on location.
Mercedes-Benz's website lets users search for dealerships by ZIP code or city and state. After the search, a list of dealers appears with their positions on a map. Each dealer has a link to its inventory, many of which include new S550s.
The selection on CarGurus and Autotrader includes mostly used vehicles, with dozens of listings for each year of the model. There are S550s with V-12 engines, special automatic transmissions. Many of the sellers on both sites are dealers.