I covered the sides, just because I liked the look of it better. I just made her two new hides out of tupperware (I painted the outsides and used a woodburning tool to cut and opening) because she was not able to squeeze her while body into her previous ones...growing! My tank is pretty cluttered, but from what I have read, they like that.
My little one is in a 20g, too...for now. ;) She uses both hides and is out exploring at night.
http://i1309.photobucket.com/albums/...ps7088495d.jpg