Apart from Böhme (2001) and Weinmann (2004) Happich won his other four titles with Gertain Wijs (2003), Meinrad Schelbert (2006, 2008) and Martin Betschart (2009) as his passengers.
[6] Entering the Sidecarcross World Championship from 1996, Happich slowly improved in the competition over the years and earned his first top-ten finish in 2000.
For the next ten seasons, from 2000 to 2009 Happich finished in the top-ten every year, culminating in a second place in 2004 as his best-ever result.
He also won two Grand Prix that season, in Croatia and Latvia, but never truly challenged for the World Championship, finishing 153 points behind eventual winners Daniel Willemsen and Kaspars Stupelis.
His final three seasons in the competition were less successful, coming fifteenth, eighth and eighteenth and taking out his last race win in Rudersberg, Germany, in 2010.