Might not be the same but had the same issue on a VU ute. Turns out the factory seam where they put the body together wasn't sealed properly. If you exhaust all other avenues try this one as well...
Remove the front quarter panel, follow the seam where the under quarter meets where the bonnet hinge joins the body. Run some black silicon across this seam (may need to take bonnet off too, not sure with a VE sorry) and down to the wheel arch. I found mine by removing the entire dash and having a hose running down the windscreen. Also helps by using a little dishwasher liquid, squirt of water on the outside and an air line from the inside (from the suspected leak site) to blow air out. The dishwasher liquid shows the bubbles from the leak site. Sorry that's so long, hope it helps