My car is getting rather old and it's headlights are foggy and dirty. How can I possibly clean them to be as close to new as possible?

The image above is what I'm chasing.
EDIT: I know of the toothpaste method and I'll be attempting that today, but are there any other methods people know of to achieve a clean headlight?



You could scrub with barely wet baking soda (water) and THEN rinse with vinegar and the foaming action MIGHT add to the cleaning. OR you could clean with vinegar, which cuts many things, then scrub with baking soda and get some foaming– Alex Apr 24 '15 at 06:42