So the high trim JDM 86's came with 4 pieces of underbody paneling. They reduce the drag coefficient by 0.01. They also fit right onto our cars with no additional modification. More info here:
http://www.ft86club.com/forums/showthread.php?t=18322
A set of 4 can be purchased here at a Japanese shop:
http://www.japanparts.com/db/parts_d...=62&submit.y=4
Anyone interested in going in on these and setting up a group buy?