I have a 2005, had it since new, and I've always been frustrated by the gap between the rear of the bed and the rail caps. My canopy won't sit flush in the very back, because of this gap. Photos attached for reference. I searched & searched, but don't see anything to level it out, so my canopy sits flush and keeps the elements out. Yes, I have rubber/foam attached to the underside of the canopy, but there's a huge gap at the rear. (I didn't feel like disrupting my canopy to get a pic, so these aren't my truck).