I’ve been out of Blender for a long time (5 months:no:). And now I felt like making a little joke.
It’s the wheel of a car of a rally driver. His name is Ken Block.
You can see one of their best videos in: KEN BLOCK GYMKHANA TWO THE INFOMERCIAL
The wheel has a white texture with just a green rectangle with the symbol of DC. But I wanted it to be even whiter. This rendering is with AAO.
Brighten it up as bit, the tire is pretty difficult to see much detail. Also for your plane below the tire, go to that material. Go to the shaders menu and check “Only Shadow” underneath Tra Shadow, by the specular and hardness sliders. It will make the plane invisible except for the shadow.
May I ask how you did the dirt on your tires. I currently have some tires I need to throw some dirt on and I havent decided quite how I want to go about it yet.
Good Job 
tdietz87:
I already have selected “only shadow” in shaders menu. But i don’t know why it isnt’ invisible. :S
The dirt in my tire was made by a texture: http://forum.cg-cars.com/gallery/displayimage.php?imageid=608
Thanks 
I think AO disregards the only shadow option. Try a render with it off. I haven’t had this issue in a while, but I think that’s how I solved it last time.
Why don’t you just add a white lamp?
Hey! Why didn’t I knew the OnlyShadow option before? 
Now it can brake! ;D
I think the brembro brake is not good. If anyone can show me a nice tutorial of a brembo brake will be good. ;D
The discs are a bezier circle and need a texture.