Indeed! Wunibald Kamm did most of his road testing on the Autobahn as did the good folks from the Porsche outfit. I have to tip my hat to Bernd Rosemeyer though,
Bernd Rosemeyer - Wikipedia, the free encyclopedia
who crashed fatally at 270mph...there is a memorial to him alongside the Autobahn. Contrary to most people's perception, the Autobahn is not even as wide as the average interstate, only two lanes per side. I have only driven it in "affordable" rental cars of small displacement. 270mph boggles my mind. The "Silver Arrows" were beautiful and decades ahead of their time.