As far as I can tell the speaker unit is in the switch module - most likely item (1) - Multifunction Control Module. Item (2) is the VMF Integral Switch Module which handles all the steering wheel controls.
Sitting Down? Maybe wise to give Mrs Colin a few weeks, I'm not sure a few days will cut it!
Item (1) 6242 RG, £426.97
Item (2) 98030642ZD £499.46
So really important to confirm this is the fault. Of course, if the switch module needs replacing you'll need to have the steering wheel angle sensor calibrated too, or the ESP system will throw a wobbly Colin.