Newsflash: there are going to be police cars in The Dark Knight Rises. And they are being "decorated" with theri GPD insignia, it would seem, in Chicago. It's only a short hop, skip and a jump from here to assume the film will be shooting in Chicago too, but that's not necessarily the case.
Anyway, if the film is shooting in Chicago, then…
No, I have no idea of what real significance that might have. It just sates a geeky curiosity to know it.
Thanks to SHH for the pic.