More than others, the 911 Carrera 4 models show the principle of causation - of action and reaction. It is the play of surface and technology. Of agility and the big smile on your face. To address the technological complexity of the features and the increased driving pleasure alike, we take you on a test-drive through the toughest weather conditions. On the steering: Porsche race driver Patrick Long. And he knows how to handle a 911 at the limits. So, take place in the passenger seat and enjoy a ride up to the icy and curvy roads on the mountain top.