 I leased a new 2010 M 35. This was my 9th Nissan/Infinity vehicle since 1996. This vehicle has been a huge disappointment. The vehicle has demonstrated low speed and high speed rpm increases while downs shifting. At high speeds, this is causing additional wear and tear on the drive train as evidenced by a large clanking noise. At low speeds, this is causing excess wear and tear on brakes. In both situations, it poses a safety hazard. Nissan/Infinity claims this is within the normal operating range, but the problem is significant and widespread as evidenced by Nissan/Infinity's own service people and engineers. Infinity will be forced to address this very soon or face a Toyota situation.