Between 1967 and 2005, AMG achieved incredible success by following a simple corporate ethos: If your pockets are deep enough, we will build it for you .

The “shoehorning” of enormously powerful, naturally aspirated engines into undersized Mercedes-Benz chassis quickly became AMG’s particular claim to fame, and displacement has long proved the company’s preferred commodity.

For those customers with the financial capability and desire to have something truly special, from April 1999 to May 2001, AMG quietly offered the autobahn-storming monster presented here: the SL 73.

Produced in an extremely limited (and never officially marketed) run of just 42 reported customer units priced in excess of 350,000 DM (~$168,000) each, the SL 73 is a snarling, snorting, actualization of “an iron fist in a velvet glove.” Don’t be fooled by its refined bodywork, supple upholstery, or 4,500-pound curb weight; it is a brutal machine capable of eating pavement (and its own rear tires) with disconcerting...