I run an Atlas topper which is aluminum. I've had great success with a couple of pairs of these lights. They are LED, dimmable, USB rechargeable (and last forever) and magnetic to a base that sticks with 3M tape. I have 3 of them but each light comes with 2 base mounts so I have base mounts where I think I'll need a light or just for ease of reach and I move them as I need. When they are on the base mount, they can rotate a bit. I've gone down some pretty rough roads and trails and not one has come off the magnetic base yet. I have only had to charge them once in about 7 months. Plus it gives you a light bar you can take anywhere - under the hood for engine work, on the picnic table dimmed for hanging out. Heading to a camp ground bathroom at night? Grab it on the way out. Going to use a pit toilet with a metal door, slap it on the door to light the inside as you go. You get the picture, very versatile.

Edit: For clarity, I have a fully built out bed with its own power system (LiFePo bank and solar array) but I still chose these for lighting because of their multiple uses.