Buzz behind the instrument panel

[El Dingo]

Just as the title says, my Superb has started to buzz somewhere in the dashboard, quite loudly, at between 2,900 and 3,000 rpm.  This has been going on for a couple of months now, and as my replacement car isn't now due to arrive until 2023, I need to fix this. There is a secondary quieter buzz from the same place that started this week, between 3,400 and 3,600 rpm.

Any ideas?

Is it easy to get the instrument panel out, so I can have a look behind it?

[El Dingo]

I found an easy way. Remove the storage box from next to the steering wheel.

I still haven't found the buzz though.