This is waaaay too late to implement for 2, but I'd better suggest this now if it's to have any chance of being in 3.
Monaco and Long Beach are good, and based on real-life races of considerable repute. But there are some city street tracks that don't host races anymore (Baltimore, e.g.), and some cities that are insanely photogenic and eminently raceable, but which will only happen in sims for various reasons. To wit: New York City, Las Vegas, San Francisco, Washington DC...and that's just in the US. Now think London, Paris, Berlin, Rome, Moscow, Shanghai, Tokyo, Hong Kong...
Imagine, if you will, a 24 hour race on the streets of Las Vegas, with all those lights, and prototypes blasting down The Strip. Or, an all-five-boroughs race in "the city that never sleeps."
The possibilities...OH, the possibilities!