I looked up the old thread from the guy who made 3D print models for fan ducts and upper/lower case covers for the S5.  I downloaded his files and will probably, at the very least, have the top and bottom plates printed up (about $40-$50 total).  Makes a lot of sense to me to confine the airflow to the inside of the unit rather than letting it escape out the top and bottom.  I'm not sold on his fan ducts, though, mostly because all the printing places I've looked at want $60-$80 just for printing that one part!  There's also a guy selling acrylic side panels and includes a bottom panel on ebay, definitely less expensive than ordering the custom 3D printed parts, but probably not as effective.