Alonso made his sports car endurance racing debut at the 1999 24 Hours of Barcelona. Paired with Antonio García, Salvi Delmuns and the journalist Pedro Fermín Flores, the quartet third in the M10 class and tenth overall in a Hyundai Accent. Sixteen years later, Alonso was due to enter the 2015 24 Hours of Le Mans with Porsche's Le Mans Prototype 1 team before Honda blocked it.