Do I need to drill holes to mount this cover?

No drilling required. This cover mounts at factory rocker points using the existing bed rail structure — standard clamp-style fasteners secure it without permanent modification to your truck.

Can I leave one or two panels folded while driving?

Yes. The tri-fold design lets you secure any combination of open panels. Just make sure the ones you fold are latched down tight before highway speeds, and don't exceed bed load capacity with open sections.

What do I need to do before installing this?

Clean the mounting surfaces on your bed rails so clamps seat flush. No sanding, priming, or surface prep is needed — install straight out of the box.