Actually, the powers that be in Chicago ordered all surplus lights from CFD and CPD to be cut up or smashed and destroyed after they left service, including the Aurora Borealis and the famous Mars crossbars from Chicago PD. That's why these lights are so rare and in demand. They were very few of them that slipped out the back door unscathed and guys who worked at CFD and CPD couldn't even get them.
One time, they buried the remains and paved a parking lot over them. Seriously, I'm not kidding, and I got that info firsthand from someone at the shop that saw it done.
I believe Greg Reynolds, the expert on all things Chicago and a frequent contributor to copcar.com, is a member here on elightbars and can verify or add more to this info. Hopefully, he will........