Hi. My cure for water or condensation: Vauxhall Insignia 2010
Remove front bumper, and headlight. Clean the top edge of the headlight where dirt collects and rainwater floods over the top allowing seepage between the clear and black seam. Shake the water out via the two drain holes, drill a small vent hole at the lowest point. Fill the upper seam with silicone. Leave to completely dry and refit. Not difficult and for no money. Cheers