In 1964, the founder's second son, Konrad Auwärter, developed a double-deck design for a service bus as part of his dissertation. The 'Do-Bus' design had extremely low weight, and could carry over 100 passengers. It also featured a low-frame front axle with forward-mounted steering gear that permitted a low flat floor. The double-deck principle was applied to coach design, creating a revolutionary high-capacity comfortable vehicle for touring. This vehicle was known as the Skyliner, and created an image for the company that differentiated the NEOPLAN brand from its competitors, and created interest in its products across Europe.