this is some really helpfull info

I'm thinking maybe a molding strip shaped in an appropriate cross section. What is sometimes called a bullnose. Shaped like a "D" but the rounded part extending out further. Usually milled wood but now also made of synthetic.

Attach to rear face of car's sheet metal. Flat part attached to car body; rounded "fin" extending rearward. This can be across the top edge, and also vertical strips on the two rear sides.

My fluids professor showed what the most aerodynamic car could look like. The tail was as long as the car and smoothed out the air stream. The front kind of had an egg shape and off course it had wheel well skirts. It pretty much look like that cars that have mph records on the salt flats. If anyone hasn't looked at these cars you should.

Speaking of salt flats, has anyone else seen The Worlds Fastest Indian? Great Movie!

A sphere yields the greatest volume with the least surface area thus the rain drop shape delivers the max payload and the tail is a 3 to 1 taper.

https://www.dassaultfalcon.com/conten...e%201%20smooth

https://www.dassaultfalcon.com/conten...ple%20fig.%202

More info here.

Paul definitely knows a thing or two about aero. I'm a newb at it, but I'm doing my best to catch up.

I was watching a show about sports balls and their evolution throughout history (History channel?) and they spoke of how the discovery of the dimpled surface being aerodynamically better after golfers noticed their old, nicked up balls traveling further.

I once found a site that listed the actual coefficient of drag for almost all production cars... can't seem to find it on google. Anyone know of a site like this?

Haven't found it yet...but this is a good place to start:

https://en.wikipedia.org/wiki/Drag_coefficient

I tried taking the wipers off of Stinkerbutt for a series of highway runs a couple of weeks ago and got nothing. From what I can tell from my past several vehicles (both truck and auto) when the wipers are running in the rain they don't start to "skip" on the windshield until over 80 mph or so, so they probably don't cause too much drag when parked at the rear of the hood. My thought is that since the aero impact doesn't cause the wiper assembly to rise off the glass until higher speeds, there probably isn't any interference from the assembly in a parked position at normal speeds.

That said, a Ford F-150 (old style) with a flat front end has a bigger problem at 75 mph or so with the wipers. A Kia Optima doesn't as does a Dodge Dakota or a Ford Windstar. The three latter have a more aero friendly front end.

Since the book was written in the 70s', well vehicles weren't nearly as aero friendly back then. It would be interesting to do a tuft test at some point using several vehicles with the tufts on the wipers.