2001 Crown Vic dies in rain

I have a 2001 Crown Vic Interceptor that runs fine in dry weather but as soon as it rains or is damp out the motor will die out and not re-start.
I have replaced the serpentine belt, belt tensioner, a/c compressor, and the battery.
Yep, the 1st day after all the repairs; it rained.... the motor died while it was sitting in the driveway.
3 Ford garages have looked at it and nobody can figure out what it is.
Any ideas what to do next?
Thanks for any suggestions you may have.

!) Open hood
2) Get a garden hose with a little water pressure.
3) Put the hose on top on windshield.
4) Watch the water roll!
5) Remove all the debris, leaves, and needles from the cowl.

The electronics, computers, and control modules on your car don't like water.

I would think that if the OP took it to three garages, they would try removing the debris.

My guess is there's moisture in the PCM or the COPs. Start with the COPs. Remove all 8 of the Coil-On-Plugs, clean the boots and springs and ensure they are completely dry. Re-install using a generous amount of dielectric grease at both ends of the spring/boot. Replace springs and boots if there are any holes/cracks. Now's a good time to change your plugs, too.