There is a small "L" shaped coolant hose on the back side of the engine by the IAC valve that leaks on the villager. It won't usaully show a leak on the ground because coolant burns off on the exhaust manifold. It's hard to see with a mirror so you can imagine what a pita it is to replace. I had the same issue on my villager and just let it drip until it got so bad that I had to replace it.