It was doomsday weather in Stuttgart. The temperature gauge read minus two degrees Celsius (28 degrees Fahrenheit) as the swollen skies emitted a mix of rain, sleet, and snow. Could it be that the whole adventure was in jeopardy? The day before, Frank Walliser, the Porsche 918 Spyder's high-strung project leader, had called an emergency meeting. There was no way that this triple-hearted roadster could be unleashed in such adverse conditions on uncompromising, low-profile summer tires. Officially, Porsche does not yet offer winter rubber for the 918. Unofficially, however, a friend of a friend of Walliser's who works in the prototype shop produced a set of black wheels shod with brand-new Pirelli Sottozero winter tires. That promptly led to another minor complication, namely the need to find space for four wheels with summer tires, not to mention the noncollapsible, four-foot-long torque wrench required to mount them.