ive had this wind noise about a year, tried finding it once too. gave up and put the dash back on.

now its getting worse and its hard to even hear talking at highway speeds. not alot of air coming through just really lloud air.

wondering if before i rip it apart in this -10 weather if anyone else had this prob. if i stuff somthing between the dash and the a pillar it goes away.

i may try baby powder with the dashpad off, and just do a blast down the highway but its messy.

 

Could it be a bad seal between the windshield and the body?

 

Try finding the missing grommet from the firewall. Look where wires or other items would be fed thru. Sounds like it's just missing that. It'd be easiest to find at night. Either put a light up under the dash and look thru the hood or vice versa.

 

use compressed air blow it under the hood along the seems where the ac box meets the firewall, then check all the rubber gromets and work from there.

 

usually its bottom of windshield being loose, comes unglued, happens all the time, ive had a few third gens like this, i had an 84 z 28 that the entire bottom of the w/s was loose and made the vin tag flap buzzing noise above about 25 or so mph
check for that

if so then for now you can go to local auto glass place and get tube of black urethane they use to glue them in and put it along bottom leading edge of the w/s

for now

til you have them re-bed the glass to the body w/s frame


good luck

 

check your floorboards.

 

Also try checking the air vents for the A/c,heater.Along with all the suggestions above.