The four-door coupe market is beginning to get crowded and the Mercedes-Benz CLS won't be alone for long. Both the Porsche Panamera and the Aston Martin Rapide will be bringing their coupe-like profiles to the party in the next few years. BMW's date to the dance will be the X6, a four-door coupe based on the X5 SUV that separates itself with four-wheel drive and a higher seating position than the competition. Power will be provided by either a V8 or a version of BMW's decorated V10 engine. The current cover of German car mag Autobild shows that publication's best guess as to what the X6 will look like when it debuts in 2009.