He joined Porsche in 1956 and won the Targa Florio, again single-handed. In 1957 under established rules which allowed F2 cars to enter Grand Prix, Porsche entered two 550RSs for the German Grand Prix, one driven by Maglioli and the other by Edgar Barth. Maglioli though failed to finish. Later that year he crashed his Porsche during the Gaisburg hillclimb in Austria. He recuperated in hospital in Salzburg with leg injuries so severe that doctors initially feared he may not walk again.