The motivation for the departure isn't clear, but there is quite a bit of speculation going on among fans of the World Series by Renault.
Ultimate boss Barry Walsh said:
"It if of course with regret that we announce that Greg is leaving us.If I had to speculate, I would say that Greg is unhappy with his results this season. I'm not sure where Barry Walsh is getting the "he has progressed from race to race" statement. Greg's average finish in the first six races was 12.2, his average finish in the last six races (including two DNF's) has been 16.7. His teammate Miguel Molina has had much more success with the team, finishing inside the top-ten in 76.9% of his race starts. Perhaps Greg felt that Miguel was getting too much attention?
"He was a popular team member who showed that he has a clear talent and progressed from race to race. We wish him all the best in his racing career."