If you're looking for more light - and if you have the stock USDOT headlights I'm not surprised - I'd recommend two things. First, E-code (Euro) lenses will make an enormous difference. (Cost is about $120 each, I got mine at Precision Volvo 978.948.7778.) Second, I'd upgrade the lighting itself. There are a couple superb halogen upgrades, and HID kits are also available. Don't upgrade the lighting before you do the E-codes as the DOT lenses will waste most of the extra lumens and blind oncoming drivers in the process. I'm running upgraded halogens (VisionPlus, http://www.autolamps-online.com) behind my e-codes and am extremely happy. Because I expect HID prices to fall and kits to improve, I've put off this mod for a while.

Driving lights and foglights do a different job. Foglights provide fill around the vehicle, and forward light is projected from a position low to the ground so as to go 'under the weather,' that is without backglare in rain, snow and fog. In the pop-up headlight days, they were also used as DRL's (at least during inclement weather). Driving lights are like supplemental headlights, projecting a narrow beam straight ahead. In most applications, they come on with your high beams. If you do modifications I suggested in the first paragraph, you won't need driving lights.

Foglight wiring is already installed in your car. The OEM kit will come with a switch and relay to connect to pre-installed wiring. A note about OEM foglights for this model: it's a fabulous foglight if (IF) you do a little extra work to correct a design flaw that prevents them from fitting in the airdam properly. If my car didn't already come with the OEM foglights, I would install Hella MicroDE foglights but use the OEM wiring.

I modified the foglight wiring so I can use my foglights independent of the headlights. That way they can be used as DRL's.
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(98 S70 T5SE misc mods, mostly lighting) (92 940GLE)