While I agree with most of your statement about the purpose of foglights, I still feel the P5 lights are useless.
The real deal is to get fogs that project low (like ours) and FAR. The fact that the lights are low to the ground prevents most of the reflections associated with regular headlights - you need them to project outward at least somewhat in order for them to be useful. And true foglights should be yellow - this really cuts down on glare and makes them more useful. Maybe if the P5 fogs were brighter, they'd be better suited for fog driving. But as is, the beam is low enough and wide enough, but not at all long or bright enough to be effective, IMO
The P5 fogs act more like curb lights (generally on the sides of few cars - they light up when a turn signal is on to supposedly illuminate the curb for turns - my old LeBaron had 'em). They don't project anywhere near far enough to be useful as any kind of real driving light.
I have driven in fog, and tested the P5 "foglights" for their usefulness - they don't really do a damn thing other than look cool (which they do very well!). Unless your only object is to light up the road 4 feet in front of the car - which doesn't really help under any conditions.
Just MHO.
~HH