Driving lights, like fog lights, are only allow when low beam HL are on in most states.
If you drive in other states, their rules when you do.
Many DMV have easy to read rules and are online.
Driving/fog light installed like pic in Fiero84Freak post will make park/turn very hard or impossible to see to other drivers. Meaning Turn signals are useless when drive/fog is on.
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)