Ok... I checked closer and it's not as obvious as the fronts. There are small zippers on the corners, but they are kind of reversed, so it doesn't look quite like a zipper when you glance.
Also. across the back, at the very bottom, but not underneath, it is at the bottom of the back... feels like a piece of cardboard, but it's really a plastic lip that's folder over under the fabric and back into another channel where it locks. Hard to explain, but I'll get pictures when I actually remove them to install the heaters.
'11 JK Unlimited Sahara - 2.5 Frankenlift, ,33X12.50 Duratracs on 15" MB72s, Genright Rockers (aluminum), WURX front and rear bumpers/tire carrier, Warn winch
'01 TJ 60th Anniversary, 2" Budget Boost, 33" BFG ATs, AFW Front Bumper, Olympic Rock Bumper, Warn Engine & Steering box skid, Kilby Gas Tank Skid, OR Fab Rock Slider Bars, Rhino'd tub - GONE