Need For Speed Unbound is a fairly simple game: you win races, make money, and buy new cars that you use to win further races. So on and so forth. That said, if you're tired of the grind and just want some cash or a cool car to race right off the bat, there is an exploit that can help you get them.
This Need For Speed Unbound money glitch relies on the game's save system, and only works with races that feature a cutscene at the end of them. It's also likely that it'll be patched before too long, so if you want to make some money, I'd be quick about it.
How to use the Need For Speed Unbound money glitch
Need For Speed Unbound's gameplay works on a weekly system, where completing daily races and returning to the garage will advance your calendar until you reach a qualifying race on the seventh day. You have to grind cash during the week to afford the buy-in for the qualifying race, and the game expects you to do this for four separate weeks.
However, by taking advantage of Need For Speed Unbound's save system, you can repeatedly take part in the qualifying race to grind money, letting you afford the qualifier buy-ins on subsequent weeks with no trouble. The key to making this work is to quit the game as soon as the cutscene starts to show at the end of the match. First, you'll be shown the car you won and told your reward, then the cutscene will play right after it.
If you load back into the game, you should have the rewards, but you'll still be able to race the qualifier again, since Need For Speed Unbound won't have saved your progress. Rinse and repeat as many times as you like to earn infinite money. Until it's patched, that is. If you want to see the full thing in action, this video by DPJ can help: