Water ingress to driver footwell via pedal area, via brake servo?

I too have the water ingress via the brake servo, water then coming in at the pedal area into driver footwell.
Much advice as to sorting the problem, servo removed, new sealant etc.
However, can anyone advise as to where the water access is that leads it to the servo seal? Via the bottom of the windscreen? Via the vent spaces showing under the rear of the bonnet lid. The rain must get in somewhere then channels to the servo area. I feel the water must somehow fall directly onto the servo, but from where? Anyone please?