So if the lens is fine on another camera, why do you hate the lens?
The fact its odd on the 30d leads to 2 possible issues. Possiblilty number one is that the 30d is in fact back focusing, but your focus chart does not indicate that (although that depends on you getting the 45 degree angle right). Possibility number two is that you use the 30d differently and this contributes to focus errors, if its a new camera to you, that could be more probable.
In the first shot the only contrast point appears to be half way back down the car with some refelction, so like someone already pointed out, maybe its not a contrasty enough subject for autofocus to work. This is why lenses still have and MF/AF switch. The 2nd shot certainly seems to have the same issue as it seemed to go for the grass in the background. The car fills most of the frame so I can only image the extreame outside points on the left and right being capable of finding a target, and they are over the grass.
One thing I have to pick up is you said "the focus points". If you are using all focus points then the camera will pick the easiest thing it can focus on, which may or may not be what you intended. You have 9 focus points, pick whichever one matches your intended composition and use it. Thats why Canon give you more than one.