I have a 2015 F350 and it has the XL trim. It does not have factory foglights, but has black plastic inserts where the fog lights would go on other trim packages. HAs anyone put aftermarket foglights in the slots? Im thinkin of doing that and wiring them into one of my upfitters.

 

You can buy an upgrade Ford light switch which contains fog switch to replace your stock switch. This can also come as a kit that includes the light sensor for the auto headlight option.
This switch is plug and play and activates the harness which is already on your XL. You then can either plug in the stock fog lights or tap into the harness to add an aftermarket fog light kit. Many are going with LED fog lights.