I only ran the first race and didn't really have the time for the rest, so I didn't really get to see the differences between cars play out.
...and to be completely honest, the driver aids were the only reason I completed the first event. I don't have the talent to keep these things on track and would likely DNF every single race within the first two laps.
THAT SAID...a couple of ideas I'm going to throw out for general consumption:
1. Rather than focus on an individual driver's championship, make it a manufacturer effort. Each car has a roughly equal number of drivers doing their best for the team.
2. Don't make all the cars exactly equal, but find some way to help the "lesser" cars. Grant them a little more engine power, maybe? Getting that right would obviously require testing time from some of the fast, consistent aliens
drivers. (with great power comes great responsibility)
If all the cars were on slightly-more-equal footing, and you have a good selection of tracks, I think you'd have a good series.