Wayne Parham Messages: 18836 Registered: January 2001
Illuminati (33rd Degree)
I've found it happens at different speeds and window locations and openings on different cars. Some seem to do it really badly when one back window is rolled down. Others do it worst when a front window is partly rolled down. The flap in the front of a sunroof reduces this effect when the sunroof is open, because it directs wind over the top instead of down into the cabin.