Fabia Elegance (estate) rear park assist module location?

Anyone have an idea where the rear park assist module might reside in my 2006 Fabia Elegance estate?

It's a factory fitted rear park assist system as per all Elegance models of that era.

The park assist isn't working (it had worked without issue for years) - nothing audible at all - no 'beep' when reverse initially selected or a long 'beep' when reverse selected which might suggest a faulty sensor.  The reverse lights are working - I'm assuming the module will take its power from the reverse lights.  This leads me to think it might be the module that's faulty.

Thanks