Could you help identify where water is entering on driver's side when washing or raining?

This car has never been garaged, never wrecked, windshield never replaced, has no sunroof and never leaked water. I hand washed two weeks ago and water leaked on driver's side front. I was able to duplicate with hose once but leaks everytime with rain. A leak specialist checked body seems for cracks and firewall feed through grouments for deterioration with no finds. He caulked the driver's door weather stripping with no affect. The initial leak with washing was in the left corner where the parking brake cable is. When it rains, the rubber boot covering the steering shaft leaks water at the junction of the two halfs.