My wife noticed a sloshing sound as we slowed and I tracked it to the left door sill cavity.  I pulled the bung forward of the left rear tyre as shown and about 4 litres poured out. 
I suspect it is entering via the inadequate foam seal between the plastic and the body directly below the left bonnet hinge.
	
		
			
		
		
	
				
			I suspect it is entering via the inadequate foam seal between the plastic and the body directly below the left bonnet hinge.