[aerohead]

Wyatt,it's hard to tell true-length and actual angles from an orthogonal projection as in your renderings.So it's hard to figure if you'd have flow separation down the back slope of the cover.Metro MPG put a template together for his permanent Kamm back project,that represents a generic teardrop shape that we think is a good starting point for design.---------------------------------------------------------- If you can rotate your image until it represents a side view of the pickup,it would allow you to place it under the template and see if your angles are within the margins.----------------------------------------------------------- If the cover descends at a steep angle,the flow will separate and you'll lose the benefit of the cover.If you can find your way to the Phil Knox aerodynamic photos in the archive,there you'll find a photo of the famous Kamm K-Car,taken in Volkswagen's windtunnel.From the smoke trace over the roof of the car,you'll be able to see the "perfect" contour up to about the last foot or so,where you can see the air separate as the roofline rolls more steeply down.If you mimic this contour,you're home free!