I need help please! Where might i find the BCM? I have a 2011 fabia vrs estate. Windows have packed up, central locking works when it fancies, and a few other quirky electrical things happen now and then.

The parts catalogue entry with diagram is HERE, but I'd also suspect the wiring bundle in the rubber boot that comes into the driver's door from the front wing.  It's a known weak spot on Octavias and I presume Fabias where insulation can harden and conductors break.