Take out boot carpet and look on boot floor to see if there is any dirty or dusty trails where water has been running. You may be able to follow trail back to where water is coming in.
Many times it is the seal around back lights.
If need be you can climb in boot with torch while someone sprays car with water to find leak. Make sure you spray under arches aswell
Don't forget that the water may have come in over a few weeks so it may only be a tiny hole.
Lift and dry carpets or you'll suffer steaming up for ages.
dave, February 2011
