Originally Posted by Blitz

Lower ISO means less noise. I guess you could also say a sharper picture, but it's not totally accurate.

He probably did shoot at ISO 400 (300 isn't one of them) or lower, because there's no reason not to if there's enough light, but by no means did he have to with a Canon 5D mkII. 22 MP and the most advanced processor Canon is making now make it a monster at high ISO. I wouldn't be surprised if he actually took these at ISO 1600, since they're far from 100% crops. My Digital Rebel (and the current Rebel XSi or whatever they're calling it now) max out at ISO 1600. The 5D mkII still has 3200, 6400, 12800, and 25600 at its disposal.

Originally Posted by Blitz

Define "something similar". You mean pictures that look like the OPs? The most important thing you'll need is the rig. Beyond that, there's no reason your XTi couldn't take pictures like these with the right lens.

Firstly, it has to be very wide. A 17-40L should do the trick. So would the kit 18-55 if you can't afford anything better. You have go wide to compensate for the 1.6 crop factor of the XTi; the OP's 5d mkII avoids this because it has a full frame sensor (though he still used a wide lens).

It wouldn't hurt for it to be a fast lens (in terms of f-stop) for the rolling shots, but probably not necessary. A good rig will make the camera stay perfectly still relative to the car while it's rolling, and you want a relatively slow shutter speed to get the background blur effect. The static shots are a different story. Getting the car to look perfectly sharp while the background is out of focus like that means the OP's lens is at probably at least an f2.8. No way around that. A good zoom that fast will cost you. Or you can get a fast prime. I have the Canon 35mm f2 and love it, especially for only $250.

Your shots won't look anything like these straight out of the camera though. That's when post-processing comes in. Besides the obvious (removing the rig from the picture), a bit of Contrast/Brightness/White Balance makes a huge difference. I recommend Adobe Photoshop Lightroom for his.

Hope that helps.