Is there a DIY bed liner that can be applied with a brush/roller that I can use on the bare metal bed of my K5? I don't need any expensive spray on liner or insert liner. I just need something to protect my metal from water/mud (specifically because I wheel with the top off and my carpet is already long gone). What can I use besides POR15 and where can I purchase it? Also, what can I do about keeping my back seat dry? Is there a cover I can buy for it or is there a vinyl seat from another application that will work in place of the rear bench? thanks.