The SW-6659 part did add auto headlights for us. Pretty simple install. There are two screws holding on a cover below the steering wheel. That cover covers the single screw holding on the headlight switch housing. After you remove the screws to the cover, there are two "clips" that release if you pull on the cover. I did NOT completely remove the cover, just enough to get to the single screw that holds the switch housing. Take that screw out and unplug one electrical connector and the original switch can be removed. You have to depress 3 fingers on the old switch so it can be removed thru the front of the housing. They can be depressed one at a time as long as you don't let one you already pushed thru snap back while you are doing the next one. Oh, the "screws" (term used in the service manual) are 7mm hex heads.
Great upgrade for just a few bucks. Thanks to the one who posted the part number.
BTW, when you unplug the original switch, the headlights come on, so don't plan to go to lunch between that and plugging in the new switch.
I think I replaced mine the not-so-correct way by getting a very thin philips in there, and wedged the thing out without unscrewing anything.
However, I DO have the fog light kit sitting right here next to me, and with that, I have a spare headlight switch. I'm willing to sell one for $20 shipped if anyone wants to do the auto-headlight mod.
I'll be installing my foglights either tomorrow or saturday. Along with a few other things (purchased a sub, and some decals!)