I just got back from a trip to Chicago (actually the suburbs around it).
Anyway, I drove by one of the local cops and the mounting position of the radar looked very "foreign" too me. I guess this is because I am used to seeing dual antenna Stalker Ka guns mounted in cars.
It actually looked a lot like a picture of the Stalker ATR ( and just mounted smack in the middle of the dash). It just look really funny to me because it was so obvious when you drive by.
It looked like a big long rectangular grey box.
Honestly though, I could be completely wrong. It might be k or ka band because I had no detector with me (wasn't my car)