Accessory Button?
 

I have an '06 Saab 9-3 2.0T with the Infotainment option. So, I have this black button with a white line on it, that the owner's manual refers to as an "accessory button" that can be used for lights, etc.

What, if anything, has anyone done with this button? I like to have all my buttons serving a purpose and so far I have three or four with no purpose at all.

I have the same button in my '09. I wish I could have it programmed toggle the 'eyebrow' lights... I'll ask the dealer at my next service.