Just finished my install this weekend.
1. One unexpected benefit of the Snuglid. Because it fits OVER the plastic bed rails, even across the top of the tailgate; it effectively LOCKS THE TAILGATE! Cool!
2. Had no problem with the six 40mm #6 bolts Snuglid provided to bolt the two frames to the bed side walls.
3. Had a tough time getting the front lid to fit down between the rear edge of the cab roof and the sport bars. You need two people; one to hold one end of the lid up and the other to futz with the end you're trying to fit. Basically you fit one side and then the other; you can't do both at once because of the outward slant of the rear edge of the cab roof. It's hard to visualize what the final fit will look like until you get one side fitted. It fits much lower than you originally think. I needed the second person to almost sit on the end I'd almost fitted to force it down into the space where it will end up. Once you see how one end fits, the other is easy!
4. My Snuglid came with the front L bracket already attached to each rail with one bolt. So I just added the other bolt and started off trying to get the front lid down close enough to the L bracket to start the screw into the captive nut in the lid. Initially, it seemed impossible! After futzing around some more I finally loosened up ALL the bolts in ALL the various pieces. THIS IS THE ANSWER! I think each install will be slightly different and thus the key is to ALLOW ALL CONNECTIONS TO FLEX WHILE FITTING! This provides a surprising amount of movement to allow you to start bolt and screws in their respective nuts.
5. Finally, I'd add even MORE tape to the back lower corner of the front lid, as well as the taping Snuglid recommends, to prevent scratching the paint on either the lid or the bedside.