I would love to use the Lotus, but it is a pretty difficult car to learn, and there are not many official races each week, lucky to get 8 official races. The community, however, is great, and I love being part of it.
The Indy car may be a good choice, however, the C-license Fixed Setup series alternates weeks between road and oval courses. To run the Indy car in full 12 week season, you would need to move up to a B-license. I believe both series run 7 days a week. There may be more one-off events for the Indy car, such as the recent World Tour events at Indianapolis and Mid-Ohio.
I think the Star Mazda may be the best bet. Easier to learn and drive than the Lotus, will force people to start learning setups (and hopefully sharing that knowledge within this community) and the series runs every day so it would be better investment for people if they don't already have it than the Lotus would. The Star Mazda series runs every day (vs. 4 days for Lotus), and several (almost all) races will go official. The Star Mazda series also splits at 20 drivers, vs. 26 for the Lotus, so you have more of an opportunity to race against people closer to your skill level. One last observation is that the Star Mazda seems to be more resilient to contact than the Lotus and the Indy Car. . . or so I have heard.
Speaking of recent World Tour events. . . . Williams F1? Just kidding.
I HATE THE SKIPPY.
