Man, I wish it was like this in real life. I see cars that I want all the time but all I can do is make a childish grabbing motion in the air, as if I could just whine and someone would give it to me for doing so. That's why videogames are great. We're already expecting great things from Need for Speed Most Wanted, especially now that we know that most of the cars are open from the start of the game.
The gameplay trailer above shows how you can just find a car and get into it. It's yours now. Like, oh, cool, there's a Aston Martin V12 Vantage. Mine now. And you can lay on the mods right then and there, too.
The trailer also shows a bit on how challenges in Autolog 2.0 will work. And billboard crashing. Again, that part is so weird.