Aufhauser started in his local clubs ASK Köflach and ASK Voitsberg. In Voitsberg he was discovered by scouts of Austria Salzburg and in 1997 he signed for the club. Soon he became member of the Austrian U21- national team. 2001 he left Salzburg to join the Grazer AK. In 2004 he won the Championship with this side. After the Red Bull take over of SV Austria Salzburg he came back to join FC Red Bull Salzburg. In 5 years he played 115 matches and shot 20 goals. Under the new manager Huub Stevens he played not often so he left in January 2010 to join LASK Linz. After the denieing of a licence and the relegation to the 3rd league Aufhauser left the club and went back for the third time to Salzburg and joined FC Liefering, the farm team of FC Red Bull Salzburg. In the 2012/13 season they won the Regionalliga West and had to play two play-off matches versus LASK Linz, his former team. They won and were promoted to the First league.
In 2014 he ended his career an became assistance coach of FC Liefering. 2016 he became assistance coach of FC Red Bull Salzburg and in 2021 headcoach of FC Liefering. He also became headcoach of the FC Salzburg U19 squad for the UEFA Youth League 2021/22.
René Aufhauser played 58 times for the Austrian national football team. He was also part of the squad for the UEFA Euro 2008.