Go with a "hard liner" like Line-X, Turbo-Liner, or Diamond. I would advise against a "soft" liner like Rino. They tear and rip much easier than a "hard liner". They also fade very quickly (dont belive them when Rino tells you they wont fade they are LYING. A friend of mine bought one and it went from gloss black to a dull gray in less than a year.) I have a Turbo-liner and I've been very happy with it. I installed a rubber bed-mat ontop of mine just to save it from the abuse of sharp edges and prevent things from sliding.
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2008 3500, QC, SB, 4X4 Laramie, 68RFE, XRT, MP-8, 5" TBE, MPH trans tune, EGR/BlueTec Badge MIA, Volant Power-Core CAI, Raptor 150,Amsoil By-Pass, Mag-Hytec Trans & Rear Diff, Lorenz Bilstein 5100 System, PSC Steering Brace, B&W GN, Ride Rite bags