Complex sentence: The only major international race held at Autopolis was the 1991 World Sportscar Championship season final race, the 1991 430km of Autopolis which was won by Michael Schumacher and Karl Wendlinger in a Mercedes-Benz C291 fielded by Sauber.
Split into simpler sentences: The only major international race held at Autopolis was the 1991 World Sportscar Championship season final race, the 1991 430km of Autopolis. Won by Michael Schumacher and Karl Wendlinger in a Mercedes-Benz C291 fielded by Sauber.