Car dies in heavy rain...

My 1997 Volkswagen Golf dies when it gets wet underneath the car. I can drive in the rain and it's fine, it only happens when it's pouring rain or when I hit a puddle. So I'm leaning towards the distributor cap or that there's an opening somewhere on the bottom letting water into the intake. I can start it back up if I keep turning it over again and again (I'm assuming that doing so just dries out the problem), or I can let it sit for like a day and it'll start back up. Anyone have any ideas?