HillustrateM8, please clarify your idea because I don't understand (seriously no offense, even though I've read yours).
Alright, let me break it down:
I imagine a career with a plot like Carbon: prove you're the best on the streets with your crew, and of course, it isn't easy with many people willing to take you down. Also, a create-your-player option with preset voices would be cool as well…
You start with some "training wheel" events to get the feel for the events that can only happen at certain times of the day, then you are released into the freeroaming aspect of the career, which is looking for events to participate in. A cool thing in another racing game, Midnight Club 3, is that if you aren't into an event for about 30 minutes, a random event will be placed on your map that you can go find and race in; otherwise, within a time limit, it will disappear, and the process repeats with another random event after another 30 mintues. There would also be an option to skip the day/night via the menu, but you would need to win a certain amount of unique events (both day and night) to unlock a tournament for cash and a prize car, which can be done at both day and night.
I can go further about Carbon's crew system, but this is basically the beginning of a career mode, and I want to make sure that this isn't confusing you.