Congrats on the car. However, I'm going to have to respectfully disagree with Don and jb. I say don't add anything to the car that would make it look more like a police car. I know of quite a few cops (friends of mine) who target "wannabe" cop cars. Having a crown vic isn't bad by its self but start adding things like a spot light or push bar or whatever, it's like putting a bright lit up sign on your car saying "pull me over". One reason cops have a problem with this is because there are far too many cases of "fake cops" in decked out crown vics who pull people over and rape, rob, and/or kill them.
Not saying that you plan on "decking out" your new ride as you made no mention of it in your op, just a friendly warning.