Re: 164 fog light mod
..what you're talking about is wiring the foglights to run as driving lights.. ie auxilary lights that run only with the high beam. this is legal, however a foglight is designed to illuminate the ground close to the car, and if the foreground is illuminated too much your pupils will close slightly to deal with the brightest part of the road, and this means you actually see less in the farfield, at the limit of your visibility in the distance where you should be looking at speed. a properly designed headlight system won't have the nearfield over illuminated for this reason.
try it out and see if it applies in your situation.. as has been said, you may be better off with a dedicated driving light.
re 100w bulbs, my tspark had 100w installed when i bought it, but the connectors and plastic immediatly around the bulb had blackened and become brittle, so i changed back to standard bulbs. the 100w bulbs in my case created a lot of heat..