There is no mention in my instruction where to install the foam pads.

Do I use them on a 6.5 box installation as well?

I see your picture has them installed to the spacer plate. Is that where they told you to install?

Thanks
Calvin

 

Slightly off topic but after seeing the damage on my 15 I sold my back rack instead of reinstalling on my 18. The holes on the insides of the bed became more of an oval shape than round, about a third longer than round. I had a 6.5 foot box on the 15 and had an installer do the install but mine sat perfect aside from the black plate having a small gap between the between edges and the plastic bed rail. I lost faith in the back racks protection after seeing how little effort it to to stretch out the alu. holes on the inside of the bed. I never really used it and just leaned against it a few times and it wasn't even on there 3 months.i dont think it would take much force to tear the j bolts out of the inside of the bed and have it smash the window. Just my opinion and experience yours may very lol

 

yes, the spacer plate would be better if it actually fit in the hole all the way around, instead of just a pin on the front side. I bought it to protect the rear window when loading an ATV. it shouldn't ever really contact the rack, but hopefully the protection is there if it ever does.