Should I take out the bed liner and have a look?

The factory ones have screws with clamps. It take about 10 min. to remove it. Take a look before it's too late. Rust never sleeps! Except is So Cal. This is a desert rust is not an issue here. Even 1st gen Tacoma frames don't rust is SoCAl!

 

So I was able to lift up the back and shine one of my super bright bike lights up there most. The paint looks pretty good. There is some debris in the low spots behind the wheels.

I also noticed that my bed liner has a foam underside to it. My guess is that this helps.

The truck lived most of it's life in the East Bay of Northern Ca. Rust isn't much of a problem. The don't salt roads ever, and truck has never seen snow I'm pretty sure.

Also, even though it's near the ocean, there really isn't any sort of "salt air" to speak of. It's very dry. Not as dry as Sacto, but dry nonetheless.

 

I would toss the liner and leave it natural with a bed mat or get a sprayed liner but I wouldn't keep the plastic, but that's just me

 

So I removed it and once I cleaned out what appeared to be a sampling of everything I ever hauled (it was my father in law's truck, but I borrowed it a lot) it appears that the bed is nearly perfect. The paint is nearly as good as the paint on the rest of the truck.

Now I have to put it back in.

 

Awesome. Told you not to look! Relax. Enjoy your truck. Keep that money for something that's going to actually break later. It will. You'll spend to fix. And you will smile. Because you won't have those huge new truck payments for a zillion months.

Stop looking for trouble. Drive it to the beach. Enjoy!