[Keith True]

Tiny,you can put a cap-plug on the end of the overflow,the kind that comes on the ends of new fuel lines and such.Then cut a little X in the end of it with an exacto-knife.It won't build any real pressure,but the water won't sneak out of it either.If hot water is hitting the windshield then the cap is not sealed properly.I do not own an A with a properly sealing cap.They all have some defect that lets the water dribble out at from time to time.I may even fix one sometime.