Environment affects evolution. Case in point: racing sedans. European sedans, contending with high fuel costs and operating on winding and narrow roads, ended up looking different from their American counterparts, raised on cheap fuel in more open spaces. Racing venues also differed, with sedan racing in Europe dominated by road racing and hillclimbs, while their American counterparts gravitated, for the most part, to drag strips and ovals.
The route for the 1963 Tour de France Auto started in France before crossing into Germany and Belgium, looping back through France and ending in Monaco. Along the way, each crew took on seven hillclimbs and nine race courses as well as each other.