You may want to check out AndrewJs thread, not as extreme as Basjoos, but good inspiration for a civic hatch:
http://ecomodder.com/forum/showthrea...amics-312.html
Oddly enough, he had better results with a low airdam and no undertray than with a shorter airdam and undertray. Im sure that can all be fine tuned no matter which way you go, but its a fun path to take either way.