Give it time my friend, give it time. You'll probably end up going through the process that we all have. Everything is great at first. Then you have some loose clamps, maybe the nut fell off during off roading, so you put them back on, then they loosen, then you tighten and then one day.... wait, isn't my bed trail deformed?For anyone concerned with crushing the bed rails - I installed the DiamondBack SE without the shims. Zero crushing (That I can see while it's installed) after 10 days and re-tightened twice. Maybe if I ever remove the cover the bed rails will be crushed a bit, but taking off the rails to install the shims seems like a huge waste of time, IMHO. Before I installed the cover I did buy a set of rails from the dealership for $60 just to have on hand. I have a feeling I'll never need em.
Worth noting - During adjusting the locking rods, one of the little red sticky tape plastic pieces that the rod slides under, got a little un-sticky so I emailed DiamondBack, they mailed me a whole set of 4, no charge.
Bed cover is phenomenal!