I read this topic years ago when I first bought my van and was waiting for this to happen. It has several times. But it is NOT from the windshield leaking. It is from condensation forming on the ceiling of the high roof van. I've noticed this in cooler weather especially. The water collects on the inside sheetmetal and runs down to the windshield. I know this because I have removed all of the factory plastic in this area and replaced it with custom wooden shelves which allows me to see (and trace) where the water is coming from. If you still have your factory trim plastic (around the sunvisors) installed, you would never see this and the water would appear at the gap where the plastic meets the windshield. Hope this helps
