Thanks for replies to other post for help.
This one is about my '90 740. there's a noise under or around the middle of the dash when I'm doing 65 or more, when it started it was at 80 and now appears at the lower speed. the best description I can give is that it's sort of like the noise from a boombox car, that is a car or van that has those big sound systems and the trunk or rear deck vibrates when they crank the volume. This is an analogy, the noise in my car is not related to radio or sound system in any way, it just sounds like that but not as loud. It seems to be in the center of the dash and may be from the air intake, but of course I can't get outside to check when it happens. There's nothing obviously loose up there either, but someone told me that the wiper assy can sometimes have a loose part that can vibrate. Any thoughts?