To me, this is the most needed feature. I say that because it will provide users with unlimited fresh experiences for Career Mode. Personally, I wouldn't mind if an Event Creator was a feature that needed to be unlocked, after a certain license level is met, or some other criteria. That way, people are still going to follow the PD designed Career Mode path, rather than JUST do their own custom events.
Right now, I think it is horrible and insulting that we have to resort to grinding out existing events in order to increase our Credit Balance so we can purchase new cars/modifications. Sadly, I intentionally did not take advantage of the unlimited credit glitch that has long been patched. Been a Gran Turismo virgin, I thought it might cheapen my experience of the game if I started off with hundreds of cars and millions of credits. I still believe that would have been the case, but at least I wouldn't be grinding Red Bull events with a sour puss on my face. LOL
WE NEED AN EVENT CREATOR!!! And it MUST pay out credits based on the difficulty of the event.