Well, it's the return of winglets and bumpy paint. As it turns out, Mitsubishi Motors experimented with dimples (aka, bumpy paint) to "delay flow separation" because the dimples/bumps modify the Reynolds number to make the cd a fraction of what it would normally be before they settled on vortex generators. I feel so vindicated, like I've been reborn anew. Nah, that's the beer talking. Here's the link.

Interesting paper. I think it's interesting that while Mitsubishi has taken the VG approach for their Evo, Subaru went with the more obvious roof spoiler solution. I wonder what the specifics are on the spoiler approach.

The winglets I've put on so far are on the plastic bumper covers so drilling holes isn't a big thing.

I'm negotiating with a manufacturer of vortex tabs for the truck. I've got to do some tuft testing next. There are several Dodge truck owners that have had excellent results (in the range of 9 mpg) with vortex creation.