Take a look at this incredible 1973 Porsche 911 Carrera RS, as it is one of the rarest Porsches seen on the road in America, even to this day. With only 1,580 built, and each optioned out to create a unique, singular car, this 2.7-liter flat-six-engined beauty has a top speed of 150 mph and hits 60 mph in just 5.6 seconds. With only four imported to the United States, Mark Hadaway's example is stunning, rare and delicious, and is the automotive grandfather of the current-day GT3.

Step inside this incredible piece of Porsche history: