How do you know?
Because he has eyes? Those images of the blue cars are definetely not in-game shots, those are definetely pre-rendered. The lighting and overall look of the materials is flawless. There are some minor defects, but CGs sometimes have those as well. Remember the KZ2 E305 trailer? That was CG and it had a huge flaw. When one of the guys launched the missile, it came out of thin air, not from the rocket launcher.
Good news Everyone!
I've invented a device which makes you read this in your head, in my voice!