[fbov]

Reading here, I understand that about the best you can do to reduce drag up front is block air inlets, and that the big drag reductions come at the rear of the vehicle. Having blocked off the front inlets, I recently did a tuft test to measure airflow across the back half of my car, in hopes of identifying some fruitful areas for modification and improvement.

I'd like your thoughts on the results.

I took video using a dashcam on a monopod tied to a chase car, and am working on editing out the interesting bits into postable size. In the meantime, I've attached a couple stills, and a verbal description of what I saw in the video.

General observations
Laminar flow is everywhere
- roof all the way back to the lip
- windows sweeping up toward the roof, right to the hatch glass
- door panels above rear wheel well, but ending under lights

Turbulent flow dominates the tailgate (lots of blurry tufts)
- lip under the hatch glass down to the top of the bumper
- flanks under rear lights sweeping forward to wheel wells

The big surprise is the rear window - near calm
- strings lay flat and don't move much
- pattern is downward with slight outward flare
- pattern extends to L/R edges of the glass, right next to high-speed laminar flow off the side windows

Granted, video will tell you more than stills, but what indications do you all see?

Have fun,
Frank