Only if police cars come with the kill switch; odds are, they won't.
@Kamaji That would cost time/money for wiring bypasses,etc,so my bet is the ones in the new cop cars will just be disabled,and can be activated if you have the right code.
I am the human equivalent of a monkey when it comes to electronics,but I have no doubt there are a good number of people who could almost hack into that stuff in minutes.
And,like the old saying goes,"If something CAN be done,it WILL be done!"