In 2004, Jan started in handful of F3000 races until one of the team partners pulled out and Jan moved back to the German Formula 3 series. Despite missing the first six races of the season, Heylen stormed to six wins and eight podium finishes to finish third in the Championship. This result lead to a seat in the 2005 World Series of Renault touring car championship, which he won. In addition, Jan drove for the winning team in the 24 Hours of Zolder behind the wheel of a Chevrolet Corvette.
It was during the 2005 season that he began thinking of racing in the United States. Careful planning and discussions with people in the sport allowed Jan to compete in the Champ Car World Series in 2006, driving for Dale Coyne’s little team. To this day, Jan will tell you that the most impressive car he has ever driven is a Champ Car, with its 850 horsepower engine and over the top aerodynamics. With Cristiano daMatta as his team mate, Heylen quickly learned how to deal with the powerful beasts and eventually scored the best finish the Coyne team had ever enjoyed up to that time, a fifth place at the Cleveland Grand Prix, out qualifying his much more experienced team mate at half the races the team ran in. The two men became great friends and to this day, Jan regards daMatta as one of the nicest guys in the sport.
Following a last minute deal with Eric Bachelart’s Conquest Racing team for 2007, Jan found himself back in a Champ Car, this time driving a brand new Panoz DP-01. Taking over the car three races into the season, Heylen, working with the engineers and crew men of Conquest Racing, developed their car from a car that was only capable of running around in fifteenth place to one capable of challenging for wins on multiple kinds of tracks, with a second place finish at the Grand Prix of Holland in Assen being the best finish of the season and the best finish ever for Conquest Racing.
From 2011 on, Jan has been racing in the Grand Am series piloting various Porsche race cars.
For 2014, Jan co-drove the #58 Porsche GT America with Madison Snow to numerous top 10 resuts and 3 podium finishes including the Rolex 24hr and Petit LeMans.