I haven't attached two side by side, but if I were going to I think I would not remove one of the side panels completely. What I would do is cut a hole in the panels that would be pressed up against one another in the middle about the same size as the hole that goes from the top floor to the bottom floor. Then I would use the spare ramps that I don't use that come with the cage and I would use those just the same way as the top-bottom ramp so that it could work as a door to separate the cages if need be. Over all though I think the 182 is not sturdy enough already. I'd hate to have two of those buggers attached and try to move the whole thing around. Maybe it would be different on a hard wood floor or linoleum or something, but on carpet I'd be afraid it would bend or something when trying to move it. Now, if it were a couple 142s it might be different, but either way I'm not sure I'd want to try.