Whistling sound

We replaced the windshield on our '98 Z3 a month ago, and now, when we are on the open road above 70 or 75 mph, we get a whistling noise from the lower edge of the windshield like someone blowing across a Coke
bottle. At least we think it is the windshield, it comes from that area where the far edge of the dash meets the glass. It can come and go with speed, or it can go away when pasing a truck or going past a hill; only to return a few minutes later. It is very annoying, and I am wondering if the windshield is not set correctly.
Any Ideas?
Democracy is two wolves and a lamb voting on what to have for lunch.
Liberty is a well-armed lamb contesting the vote.
  Click to see the full signature.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.