I have a friend who went to the police station to ask if it was ok and the cops said its illegal but since he was nice and concerned about breaking a law the cop said he would let him keep it on and if he got ticketed to come see him
then again thats just luck
trying to trick you to leave it on so you get ticketed...and then when you come see him he'll pretend like he doesn't know you...he'd probably get in trouble by his boss. You can if you want, but one thing I know is to NEVER trust cops. They can and will use deception and lies to trap you. His boss won't mind him doing that, trust me.
My friend has lights on his celi but not the big long tubes...he has little LEDs which are hard to find. One time a cop pulled him over and he turned them off, and the cop said he swore he might have seen something but couldn't find any light tube underneath the car!!! lol. So he didn't get a ticket for that. Just 4 other tickets for other illegal stuff hehe including speeding. All tickets are going to his Pre-paid Legal attorney.
Never trust cops. If they say "You have to tell us everything right now...or you'll be charged with obstruction of justice!" That's a lie. You have the right to speak to an attorney first and he/she can talk for you.
One cop wrote down on my ticket that he clocked me at a certain speed when I know I was 10 mph below by the time he clocked. He just lied to make it stick in case I took him to court. Well the ticket became a parking ticket anyway...
While he was busy doing paperwork after he said I could go, I floored it out of there to merge with traffic on the freeway at about 85 mph!
NEVER TRUST COPS.