Infiniti has been working on an updated version of their M model for 2011. They originally planned to have it for 2010 but needed to go back to the design phase to rethink aspects of design and performance.

Now, after missing the 2010 model year, Infiniti is back with a third-generation M sedan with improved power and features, and again offered with either V-6 or V-8 engines.

Exterior styling follows the trend toward more aggressive overall proportions" put forth by the auto maker. In the rear-drive M37 and all-wheel-drive M37x, the new 3.7-liter V-6 engine develops more power than…