Obscure Late 2000's Television Animation.

    This is something that has been bothering me for as long as I can remember, and has been in my memory since I first saw it roughly eleven years ago. When I was about toddler age, I saw a really cool CGI animation on what I think was HBO. The animation wasn't very long, and it featured five or six faceless copper colored figures racing along separate tracks in what I remember to be a fully rendered city. brownish in color. If anyone has seen this before or knows the name what I've described, I'd love to hear about it.