I opened the panel to change the stop light that was not working. I am not sure what the last bulb was for?

The first row one is the brake light, second row is the backlight, third row is the backing light and turn signal, what is the last one for?

 

Foglight? Not sure so here's a bump

 

I think the second one on the left side is an auxilary rear-facing fog light. It's a safety/visibility feature.

 

Where is teh switch to turn the rear fog light on in a 2007 Volvo s40?

 

I believe the 2007 dash is similar enough to my 2005 that it's underneath the headlight switch to the left of the steering column. The buttons should be front fogs, fuel door, and rear fogs. The rear fog button should illuminate an indicator on the instrument cluster.

 

Thank you Usufruct and others.