Okay, so who's going to organize a series, or even a challenge? Lately, all I see are challenges that go nowhere (other than the GT40 at Grindelwald.) Here's some ideas:
Choose a car, and track combo. Give points to the top laps, and whomever has the second-worst time (yes, you read that right), gets to pick the next track/car combo.
Why 2nd-worst? They will have almost no advantage in choosing the best car/track combo, becaus ethe best will always pick combos to thier liking to cement their lead. The worst driver will sandbag, just so he/she can run an Escudo at some easy track. If the best driver is really the best, he/she will not need to be preparing for the next event that will just make the championship a leader's paradise.
Other ideas would be to run a race series that involves the best 5 laps; running an event using the GT-All Stars, Gt500 series, etc. to show who can consistently race fast times and make racing manuevers that are legit against other cars (even if they are AI cars). Thnk of it as lapped traffic. The best start-to-finish time (total time) of 5 laps will be the winner. This way nobody pulls a one-time corker of a lap to be champion. After all racing is about who's quickest in the end, not in the middle!
Just some ideas.