I highly recommend the bedliner under the fenders and running boards. Cab too!
It doesn't hold water as stated previously. What it does do is:
-Prevents stars in the paint from thrown rocks from the tires.
-Prevents rust under the vehicle.
-deadens sound from the single layer of metal of the fenders.
It can also be painted to match the vehicle finish. But who would want to do that. I looks good black.
Frank
