Will this fit my bed without any drilling or permanent modifications?

Yes. It mounts at factory points on your truck bed—no drilling, no brackets welded to the frame. Basic hand tools get it mounted.

How waterproof is this when the panels are closed?

Hard panel design sheds water and won't leak at the seams when fully latched. The panels stay rigid and keep the bed dry in heavy rain and at highway speeds.

Can I access my entire bed without removing the cover?

Yes. The tri-fold design lets you fold all three panels flat against the cab. You get full access to the bed floor, then fold them back down when you're done.