All kinds of possibilities I can think of for buzzing/vibration sounds in the upper center console region.

First, have a passenger verify where the sound is coming from. I've been misled many times guessing where a noise is coming from at road speed to the point of being almost certain, yet out by 2-3 feet. Even better, give them a mechanic's stethoscope or hard piece of plastic/vinyl tubing to hold close against (not in) their ear to find the loudest area. Once you've got that more precisely narrowed then try to make it temporarily go away by pressing on things, moving things a bit, taping things together, whatever it takes to make things a bit different. You know your car best, so make yourself the passenger.

o Does it vary by road surface? if not then possibly a relay buzzing that normally doesn't buzz. Try turning off your headlights at speed. Access the relay tray and wiggle/reseat all relays then try driving again. Drive with access to the relay tray open and put your fingers on each relay -CAUTION some relays run very hot, consider gloves.
o Operate the heater controls, air vents, move/press on the louvered dash vents, and vary the fan speed.
o Press/push on the defroster vent(!!) plastic bezels and the windshield trim
o Open the glove box, push on all sides.
o Push on the switch panel, especially the thin trim around the heater control panel.
o Push on the console side panels and under dash panels

Those are the kinds of noise areas I've encountered over the years in 900l/700 dashes.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now