I have spent a fair amount of time lying on my track mat underneath my Echo trying to figure where the most productive underbelly additions could be made. The areas in front of the rear axel are pretty clean, particularly in the mid-car area. In addition, Toyota added a small flow smoother behind the front bumper. The area behind the rear axel is a real disaster. It has lots of rough protrusions and lots of “vertical” wall sections in front of rear bumper - pretty typical on many cars. (See the first three pictures which reflect these problems.)
Spending still more time on my back, I quickly concluded that though a rear belly pan would be helpful, there was no way to attach one. So I set about designing and constructing a light framework using small aluminum channel and angle, purchased at Lowes. I also had to add some attachment points for the framework. (The fourth picture shows this framework.) The lower bumper cover was planned as the rear attachment point for belly pan .
With the framework in place, it only remained to cut the coroplast in two pieces, one large, one smaller, and to attach the coroplast to the framework with self tapping screws. Note the section of aluminum flashing which was used in the area of the exhaust pipe. Also note that the muffler is left uncovered to maintain cooling.
I plan to do some
ScanGauge testing when I can return to my baseline test track in a couple of months. Obviously, I won’t be able to do the more desirable A-B-A type test, but my previous baseline should support some rough conclusions