It wasn't long before we crossed what had been the East German border, the prow of our borrowed black Rolls-Royce cutting a clean line through arterial highways out of Berlin. Highways turned into two-lanes, two-lanes into little village streets, until we pulled into an unassuming edge-of-town industrial lot. On a far building, on a corner, stood a little Porsche crest. This is the home of one of the most secret cars in the world, a hidden product of two men in a fit of reciprocating and all-encompassing madness.