Here's my spats:
http://i3.photobucket.com/albums/y93...y/DSCF0837.jpg
http://i3.photobucket.com/albums/y93...y/DSCF0840.jpg
http://i3.photobucket.com/albums/y93...y/DSCF0838.jpg
Wait... Blocking airflow will cool the engine? You've got it backwards, dude. Blocking the grille makes the engine run
hotter. Just ask NASCAR drivers when they pull tape off their grills during a race. More airflow=cooler engine. Less airflow=hotter engine.
The cosmetic rear spoilers don't do much of anything. However, a decent spoiler will in fact reduce lift by creating downforce. This is if they're either shaped like an upside-down airplane wing, or like the old NASCAR lip spoilers. Granted, they do generate drag.
However, a full belly pan covering the engine results in a hotter engine, reducing efficiency and lowering the life of the engine and parts. Vents/loveurs for the engine bay would be beneficial.