My 2002 Honda Odyssey is making a terribly whistling sound which appears to come from behind the dashboard (sounds like a turbine spinning). The noise only occurs when traveling over 40 MPH and when the weather is warm - faster speed increases the noise. The dealership tells me that it is the that the cowl is warped. The cost is over $300. I am planning on getting a new van and I don't want to spend $300 on this one. Any remedies? Thank you, guys.
Although maybe not for your particular model year, a search on whistling will give you lots of ideas and things to check, but essentially all do with filling potential gaps where air passes (using foam weatherstripping or silicone).