I do a lot of driving on backroads at night and also used race pro-rally so lighting is important to me. Sadly, my CTS is a model that came with halogen headlights so I’ve been looking into ways to improve on that. The two most logical ways to go are to convert to LED or HID. I’ve spent quite a bit of time researching the choices and finally decided to do the logical thing and buy both. I purchased them from Headlight Experts (who I am not endorsing, but seem to be among the more reputable...
Another headlight LED conversion question
Another headlight LED conversion question