In 2008, he returned to the 24 Hours of Zolder and Belcar GT with AD sport, racing alongside future Porsche Factory driver Laurens Vanthoor.

The 2009 season saw his final attempts at the 24 Hours of Zolder and Spa, resulting in a DNF with AD Sport, and a fourth-place finish with Prospeed Competition, respectively.

He beat out Nicky Pastorelli for the 2006 Champ Car World Series season at Dale Coyne Racing by bringing sponsorship from the Muermans Group and BergHOFF Worldwide.

With Cristiano da Matta as his teammate, Heylen scored a fifth-place finish at the Cleveland Grand Prix, the team's best result to date.

The pair earned three podium finishes that season at Lime Rock Park, downtown Baltimore, and Road Atlanta's Petit Le Mans.

In 2011 Heylen drove in the 24 Hours of Daytona for Starworks Motorsport and made six starts in the FIA GT3 European Championship for Prospeed Competition and finished 27th in points.

[4] Heylen and co-drivers Madison Snow and Marco Seefried finished in third place in the Rolex 24 At Daytona, as one of only two GTD entries to use only three drivers.

While he only competed in one event in 2016, Heylen came back in 2017 with Wright Motorsports for a full season in the Pirelli World Challenge Sprint X GT Pro/Am championship, racing alongside Michael Schein.

The 2018 and 2019 seasons brought more partial runs to Heylen's resume, running select events in the Continental Tire SportsCar Challenge, the 24H GT Series at Circuit of the Americas, the Chase for the Trigon Trophy TA2 Series, the IMSA Prototype Challenge Presented by Mazda, and the Pirelli GT4 America SprintX Pro/Am championships with VOLT Racing, RS1, Wright Motorsports, and Baker Racing.

At the season finale event of the Intercontinental GT Challenge's Indianapolis 8 Hour, he joined Poordad and Root, securing victory in the silver class.

The championship titles were decided at the season finale at Road America in dramatic fashion when aggressive racing by the BMW withdrew the team from contention and the No.

In the IMSA WeatherTech SportsCar Championship, Heylen joined fulls season drivers Patrick Long and Trent Hindman in the No.

In 2008 and 2009, Heylen acted as the Volkswagen Jetta TDI Cup chief driving instructor, overseeing the training of 30 drivers between the ages of 17 and 26, hoping to make it in professional sports car racing.

[8] In the 2019 season, Heylen returned to a management role, joining the Mazda Road to Indy's USF2000 series as Race Director.