Ideas for Rubber bedliner

They are 17" 4runner sport rims with bfg all terrain tires.

 

I used to work at a mine and we were always replacing 36 & 48 inch wide conveyor belts for hauling ore. We used to just go out to and cut it to whatever length we wanted. A lot of guys made bed mats out of them. The company would give it away. You might look and see if there's a mine or an industrial plant of some sort around.

 

I planned on buying a rubber mat eventually, but just as a temporary fix, since I already had it laying around unused, was some of these foam/rubber mats from harbor freight... We originally had them under a treadmill, and after we sold that they were just laying around. I took 6 of the squares, attached them together and they just about fit the shape of the bed perfectly. All I had to do was cut out the wheel wells.