My work truck looks like this most days. I spent 4-6 hours per day driving in remote areas/off-road.

I have more sensitive gear and equipment I need for my job in the back seat The bed is also usually full of equipment that is not as sensitive.

I keep a cooler full of water and several boxes of granola bars inside.

So whenever I fill up the tank, I spend a few minutes tossing trash out of the truck. It's the only way I have found to keep the pile of mess somewhat under control.

Once I year I clear out the truck and have it detailed to start fresh on the dirt buildup.