Automakers like to push the limits of design and technology with concepts at motor shows across the world. But for every prototype that hits the stage, there are others that never even see the light of day. Porsche is finally taking the wraps off some of their never-before-seen vehicles in Porsche Unseen. Ranging from 2005 to 2019, the book features 15 top-secret designs accompanied by phots from Stefan Bogner and text written by Jan Karl Baedeker. Its 328 pages give an unprecedented look into the German automaker's creative process showcases every step from the first sketch to the finished product. Among the models are the 919 Street, a Vision Spyder, and the family-friendly Vision Renndienst van.