I recently found a lot of water in the front passenger footwell. I went on loads of sites and tried all remedies. Finally found out tha where the wiring comes from the headlight it passes through the inner wing to get to electrics behind the dashboard. Where it passed through the bodywork there is a grommet to prevent water ingress. This grommet was so loose around the wires that water from plate under the bonnet ran down the inner wing and tracked down the cables through into the car. To got to this grommet you have to remove the inner plastic splash guard inside the wing. I then put lots of sealer round the cables and the grommet and this has sorted out the problem. Had tried everything else a d have not seen this solution on any site. Hope it will help.