Couldn't find the other thread with the aerodynamic discussion, so I've applied here. Basically, I fabricated these out of light gauge aluminum panel and break formed certain edges to correspond with the underneath rear chassis and directly attach to the leading under edge of the rear bumper. It was this area that I felt was a catch 22 wind situation where it was holding some speed wind captive at top end. Here are the two outer end pieces that are on the outside part of the rear chassis longitudes. The center piece is a simple copy of these but just longer in length. They pop in easily with some good rivets.
