Sure are! I can't remember the exact measurement but I believe it was right around 0.45 - 0.5 cubic feet internal volume. I was going to make another one with reduced volume by filling up some of the internal space. As for sizing in the truck, it's the same footprint as the storage box that is under the back seat already. Hope that helps
I love my 2016 canyon but wanted to put subs in the back without sacrificing seating area so i put my fiberglass knowledge to use and built a custom molded fiberglass downfire subwoofer box to fit under the back seat of the crew cab models. Let me know what you guys think! P.S.They are available for sale