Will these work with my tonneau cover or bed liner?

Yes. These caps mount to the rail itself and sit low enough that tonneau covers and drop-in liners install normally. Just verify fitment before final mounting.

What do I need to install these?

Installation uses factory mounting points — you'll need basic hand tools and fasteners to secure them to your existing rails. Hardware specifications depend on your mount method, so confirm attachment points during test-fit.

Can I paint these or do they come finished?

Finishing is not specified — test one panel first to determine if prep and paint are needed for your desired appearance and protection level.