water leaks

talcom powder around the seal/windshield area, compressed air from inside. cloud forms where leak is...I don't remember if this was in the FSM or ? It may have been what the techs did to find leaks at the dealership.
You can use sopy water also and it will form bubbles etc. but yes you need a higher pressure air situation inside the car...i remember starting the car and running the heater full blast with windows up etc. If you can pump compressed air in there even better and quicker