• All Original Equipment Vehicles, Ford, Chevy, Dodge, after installing a bugshield can make noise due to redirected air, however CHEVY/GMC are the most likely to have this issue. They noise you are describing, “crackling noise sound at the top of the windshield at highway speeds” is simply caused from loose trim that runs down the sides of the windshield. The noise will happen at about 60 MPH and it depends on which way you are driving into the wind. 
• Good installers will either install tape or run a bead of caulk in between the trim and the windshield when installing a bugshield on these vehicles, preventing the trim from contacting the glass. 
• If you are experiencing this, you can fix it by one of these two methods, easily at home. 
• Other noise can be caused by the plate under the windshield wipers or a strip of rubber under the hood which it’s only purpose is to cover some screws or bolts on the vehicle. This piece of rubber can become loose and create noise. 
• All of these noises can be easily located and fixed to stop the irritating noises.

If you watch closely you will see that Ford F150 hoods after 2004 were manufactured out of a lighter composite material, therefore the hood now bounces where the hood meets the windshield. This happens without a bugshield installed; when a bugshield is installed it can aggravate an existing problem. Stampede recommends using a very low profile shield and taking your vehicle back to the dealership to have them fix the hood issue as described in the attachment. Attached is the Notice From Ford on the issue.