Completely agree on the whole one light thing, it's totally dangerous in the weather we are having at the moment. Combine this with the number of people who drive on sidelights + front fogs, or no lights at all, its rare to see someone who's illuminated properly!!
Having said that, I did have a strange issue where my Focus kept eating cheap LED sidelights, which caused the bulb failure circuit to stop one of my tailights from lighting up, or it would light up very dimly or very brightly like a rear fog. I got flashed at a lot that night!