I quote one of Bob's posts :

"I finally managed to upload several photos of the bustle described in
my post 30580. We have achieved as high as 28 mpg at 60 mph with this
addition. It is tube and rag, (dacron) as in early aeroplane
construction. It lifts to gain entry to the engine and is easily
removable. Bob Parsons"

Gracias,
 Miguel