OK, someone has to have found a way to do this. I have an '06 GMC crew cab, came with plastic bed rail caps, with no covers for the 4 holes. I put a new tonneau cover on, which covers about 1/2 of the holes, leaving the other 1/2 open. I want to plug or cover these holes.
I thought about puting some of those flat flip up tie downs in, but they'd be useless as tie downs because of the tonneau. I bought some plugs off ebay for this exact thing, but they don't fit the plastic bed rail caps. Any one make thier own covers? Find a GM part # that fits? Find after-market bed rail caps with out holes? Remember, mine is the 1/2 ton crew cab, with the 5'8" bed.