In 1928, Igl joined BMW as a motorcycle designer and worked on models such as the BMW R5 and BMW R51/2. During his career at BMW, he was also involved in car design, including the BMW 501 and BMW 507, both of which were very well received.
In 1952, Igl left BMW to become design director at NSU Motorenwerke AG, where he contributed to the design of the NSU Prinz, a small car popular in Europe in the 1950s and 1960s.
Igl also taught industrial design at Munich University of Applied Sciences and was a member of the Association of German Designers (VDG). He received numerous awards for his design achievements, including the Industry Prize of the Federal Republic of Germany in 1964 and the Bavarian Culture Prize in 1983.