[janitz]

Euro switch is what you'd want to do this, disable the DRL and then use the switch to turn on the fogs without turning on the lights.

Not sure about HID in the fogs, you'd need to install a ballast and a different harness, etc. Can't just stick an HID in there.

If you wanted something different in there I think an LED based light would work and give a different look and I don't think they need special wiring.

 

[janitz]

What should I look up?
Any links you could provide is infinitely helpful.

This is just from a quick search on Amazon.

http://www.amazon.com/Generic-LED-9-H1-6000K-Xenon-White/dp/B0026766CQ

They basically just fit right into the socket.

Based on what you want to use them for, DRL they might be what you want over the HID which requires some work with the Ballast (although not as much as I thought based on Indytom's post).

The LED should be a brilliant white light, basically what you see on new Audi cars with that light eyebrow strip for the DRL.

Just to note for anyone thinking of these LEDs, they're not really good for your headlight, the color temp may be 6000K but that doesn't actually measure light output which is in Lumens. These don't list Lumen output because I'm quite certain it is going to be low.

 

[janitz]

DRL's (low beams) are on all the time. Fogs are on with low beams only (DOT). If you want to use the fogs as DRL's just wire the fog light power lead to switch 12Volts - ignition on, DRL's on. You will need to remove or break the connection from the light switch controlling the fog lights. Basically not a good idea due to DOT requirement that fogs are to be turned off with high beams on.

No...

Just replace the North American switch with the Euro switch and disable the pin that controls DRL function.

The Euro switch has an extra switch position in which the fog lights are on and the low beams are off.

North American switch with default config:

DRL on automatically
Low Beam
Low Beam+Fog
High Beam (no fog)

When he disables the DRL and switches to the Euro switch he'll have these options if I understand things correctly:

DRL off when car in drive
Low Beam
Fog
Low Beam+Fog
High Beam (no fog)

Someone with the Euro switch will know for certain.

 

[janitz]

Yah, fogs on with high beams is against the law.

So now all your lighting is illegal and dangerous.