BMW is well represented in the luxury coupe market with the 6 Series, a model that accommodates four adults and moves briskly thanks to its 360-horsepower, 4.8-liter V8. However, this Bimmer pales in comparison to AMG models from Mercedes-Benz, and lacks the visual appeal of the Porsche 911 Carrera. To combat any relative styling and/or power deficiencies, the 2006 M6 is a must-have for BMW to remain competitive in this highly-exclusive yet lucrative niche of the market.