Porsche saved the best for last with the 997 generation of the 911.

The GT3 RS 4.0 was the culmination of years of testing on the open road and in the crucible of motorsport.

Its engine was the most powerful naturally aspirated flat-six built by Porsche at the time of its unveiling, producing 500 brake horsepower at 8,250 rpm and 339 pound-feet of torque.

The enhanced output came from a new intake manifold, higher-flow air filters within carbon-fiber housings, less restrictive catalytic converters to reduce exhaust back pressure, Variocam-Plus variable valve timing, and a two-stage variable induction system.

Even though the standard 911 GT3 RS was already on a diet, Porsche managed to trim a further 22 pounds from its overall weight by fitting carbon-fiber front fenders and a trunk lid, along with titanium connecting rods and lighter interior trim.

To many enthusiasts at the time, this was the ultimate iteration of the most radical road-going Porsche 911 and a car to be treasured ...