Or, near vertical. Has anyone actually tested whether you can mount the blinder vertically? It sounds like these things do not rediate evenly, so it seems like it is a bad idea. I just got an M3 and it is not good for blinder mounting (see http://www.radardetector.net/Where-t...W-Z4-3344t.php for a similar car and the same (unanswered) question).
How about behind the lower mesh? It's very open, but would clearly block a little light.