The first is a truck bed liners. The truck bed liners protect the truck's mattress from scratches and damage. Liners make it easy to clean up after your job since all messes will be contained within them. All that is changing with the new generation of truck owners. With the aid of DIY tools, they are now able to tackle the job of trailer and boat hauling. They do it with style and some incredible results. Many auto enthusiasts are avid do-it-yourself (DIY) tool users.