This Landaulet concept gets an uprated V12 engine, co-designed by AMG.  The 6.0 litre machine cranks out 612 horsepower, and 738 ft-lb of torque from 2000 to 4000 rpm and from 4800 to 5100 rpm.  With twin turbochargers and water intercooling, this engine is a step up from the V12 found in the 62 S - the most powerful production limo.