Vonka began competing in the N-GT class of the FIA GT Championship in 2002. He began competing more regularly in FIA GT in 2004, when he finished ninth overall in class, improving to finish sixth overall in class in 2005. In 2006, Vonka competed at the 12 Hours of Sebring. He also raced for Wiechers-Sport at the FIA WTCC Race of the Czech Republic.
Complete WTCC results
(key) (Races in bold indicate pole position) (Races in italics indicate fastest lap)