I swapped out the headlight bulbs in my F-150 and my wife's Civic for LED bulbs. What a difference, like night and day! The Civic was a PITA because of the way the housings are built and installed, but the F-150 was easy. Just slid the whole headlight housing out, changed the bulbs and put it back in again. Scraped the heck out of my hands trying to get the Civic done and finally had to get my wife to reach in there and do it, she has much smaller hands. I also gave the Civic lenses a cleaning to get the fog off of them. That, alone, made a major difference. I've still got to change the fog lights, signal and parking lights on the F-150.
All it takes to make an LED bulb "polarity free" is a bridge rectifier on the input side of things.