[Christ]

winkosmosis -

I say that because the largest percent of them that I've seen AREN'T flat on the back. They've got some stupid rounded shape that forces the air up, making an attempt at clean separation, but leaving an obviously larger wake. If the cargo carrier had a true downward taper at the rear, it would still be better off backward in some cases, because the front of them almost always has a stagnation point lower than the horizontal center of the box itself. A flat "pig nose" with faired/rounded edges tapering back into the same shape as the front of those cargo boxes would be the best solution, I believe.

Of course, I've never done any testing on this, because I carry everything inside/behind my vehicles. I'm not aware of any wind tunnel testing by Thule, either, but they can still make claims that their boxes are aerodynamic, right?

*(Of course, they're protected by semantics in their claims, because the word aerodynamic is abstracted to mean so many different things, and if they could prove something so stupid as the box providing added lift - negative or not - they could be safe in saying that it's "aerodynamic".)