Woodgie1 - I mean this in no disrespect to you at all, especially since you have absolutely zero control over this, but in the United States of America, "the land of the free", (well, used to be anyway), we now have so many laws, regulations and restrictions that we now live in a police state. The U.S. has more citizens in jails and prisons than any other country in the world, even compared to totalitarian governments/dictatorships like in communist China, North Korea, Iran, etc. As an American citizen, I find this absolutely shameful and also very frightening. This is not the America I grew up in. This is not the America I know and love.
What I mean here is that with so many laws now and with many of them having rather serious consequences if you violate them, the citizens would do well to avoid run-ins with the law. Hence my advice regarding the original posters question about modifications to original equipment lights being legal or not. Again, this is in no way aimed at you at all. You seem like a very decent fellow, but unfortunately with increasing frequency, police officers have seem to become out of control and above the law, doing whatever it is they so wish. Again, this is frightening.
In the U.S. we now have police officers dressed in black, (sometimes with black masks on hiding their faces, what's with that?!), with assault rifles, helmets, goggles, the whole bit, as if they have become a paramilitary unit. Witness the tragic Boston bombing incident not long ago where police officers went from home to home, pounding on citizens doors and at gun point ordering they evacuate their private homes, running down the sidewalk with their hands over their heads, as if they were prisoners who would be shot dead if they didn't comply! I had tears of rage in my eyes as I watched this transpire on national TV with my own eyes! What happened to a search warrant? Unreasonable search and seizure? Roadside police roadblocks where citizens are detained and questioned without probable cause, as if we have become Nazi Germany; "Where are your papers?!" Citizens in states that have open carry laws that are carrying their firearms being stopped and illegally questioned by police officers, their firearms confiscated and being arrested when they have done no wrong! What in blue blazes is going on in, "the land of the free"? Where is the respect for freedom, liberty and the U.S. Constitution which makes, (or made), America what it is...or was? Do police officers still take an oath to uphold the U.S. Constitution? Why is it that I don't see police cars with the motto, "To Protect and To Serve", on the doors of squad cars anymore?
Police departments across the country are now gearing up with actual armored personnel carriers, machine guns and other heavy duty military equipment. DHS is doing the same thing, ordering massive quantities of ammunition that exceed what the entire U.S. military combined uses. It sends a chill down the back of Lady Liberty!
"There's a reason you separate military and the police. One fights the enemies of the state. The other serves and protects the people. When the military becomes both, then the enemies of the state tend to become the people" - William Adama