Took these pics from one of Blim's vids because of the Sniperhunter bitching.
Image set 1 Below
Here's an example of the cloud movement. The difference between lap 1(img 1) and lap 2 (img 2).
Clouds move, deform, overlap like ... clouds. Also you can see the difference in light between the laps. Because the light is moving (sun is setting), during the second lap there is less contrast in the image, the road is darker, the bushes and mountain are darker.
Image set 2 below:
In this second set of images there's some other techniques I've noticed. First image shows how the intensity of reflected light changes depending on material. Look at the circles on the rear of the car. I'm guessing they are a matt black vinyl that is less reflective then the paint underneath. Also you can see the deformation on the side of the car creates shadow itself.
The second and third image I wanted to show the light change again and how the changes the environment. I'm afraid one's internal the other external but you can see the light and clouds have moved in the third image leading to elongated shadows of the banners in the third image, and higher intensity light above the mountain as the sun sets behind it.
Lastly in the second image, the back of the maserati has its name written in chrome lettering with a chrome lip above the number plate. You can see a bright green reflection in this chrome. This is the reflection of the banner behind the car, that you can also see in the thrid images rear-view mirror.
The Evolution team have done a lot to try and make the environment seem "alive", hopefully in the future the developers will talk more about the tech they are using.