Trying to prevent wheel well rust on Ram Truck

Spraying Fluid film rust preventative inside the fenders in the truck bed area. Rusty truck pictures are not my truck. I had a Ram with the same problem but I didn't get good pictures of my truck so I found a a couple of pics off the internet for reference. If that truck belongs to you I hope you don't mind me using the image for reference. All steel trucks rust especially in the northern (Rustbelt) of the US and Canada. I'm not picking on Ram specifically. I received no money from fluid film and this is not a paid endorsement.