I had to take off the star/hand nuts and fiddle with the stop bolt things that engage the latch. Once adjusted I put the star nuts back on to maintain the position of those bolts. Now the cover sits perfectly flush and seals against the tailgate. Also, my latches have lots of "bite" and there's no way they are popping off unless I grab air and come down super hard... even then they might hold, but I've not put my truck through such paces, yet. (As a simple test I hit a big speed bump in my work parking lot while going a good speed... other than getting the security guard to holler at me, nothing happened.
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