In 2009 Cöster jumped his last competition. The pair competed in several international Championships. In 2003 Ahlmann and Cöster won the individual and German team Gold medal at the European Championships in Donaueschingen. Two years after they became 5th at the European Championships in San Patrignano.
During the 2007 European Championships in Mannheim they obtained the bronze team medal and 8th individual place. The combiantion also competed twice at the World Cup Finals, both times in Las Vegas, USA. The last time was in 2007 where they concluded with a 6th place. Cöster was also Ahlmann's partner in crime at the 2006 World Equestrian Games in Aachen and The 2004 Olympic Games in Athens. Both competitions were good for the bronze team medal.
https://www.youtube.com/watch?v=agvMGBWLB78