[Shrek]

I was anal and did both! I like it because the mat really keeps things from sliding around (normal driving).

After it flattened out from being shipped rolled up, it stays in place pretty well without using the adhesive strips. I like this because if I ever have anything really messy it is easy to remove it.

This exactly where I'm headed. I got the bottom only bedrug, which I love for everyday.
I use my bed as a truck far more often than a truck bed. When I need to use it as a bed, I just pull out the bedrug.
Do I have to? no, but I don't want it getting stained and nasty.

The bottom only bed rug was fairly cheap too IRRC.
Just need to get the bed sprayed for the few times it has actual truck dootie.