On our AF 1150 I need every inch of room between the wheel wells so fortunately the truck came with a spay on bed liner that is unknown to me but works well.
The last truck (in sig) came with a tonneau cover that I transferred so it keeps the sun from fading it. Only problem I've had is adjusting the truck under camper when too close or low, it kind of rips the liner but that was my fault.
I have about 1/2" clearance or less on each side of the slide in between wheel wells so a corrugated plastic liner would eat into that space.