1998 Volkwagen Cabrio (Afraid of the Rain)

I bought this used car about a year ago and everything was fine with the car until it rains or I take it through the car wash. In either of those cases the car will just stop on me. Crazy thing is that a few hours after the rain has stopped it works just fine.

Some part of the ignition system must be absorbing moisture and as a result breaks the electrical current.
It could be wet coils, spark plug wires or something else.

You can do a quick and simple test yourself.

When dark, start the engine, set the parking brake (which should be set any way) open the hood and look at the plug wires and cap for a blue spark jump.

If you do not see anything, using a water spray bottle, lightly spray each plug wire one at a time. (Cover the other wires with a plastic shopping bag or whatever)

Spraying all at the same time will make it hard to identify the culprit.

Although, if you do see spark jump and the wires are old, you may want to replace all of them.
However, you may want to replace one wire at a time to avoid mixing them up.

While spraying the wires, ensure you keep the distributor cap DRY until you are ready for it.

When stalled, you could try spraying some WD40 over the cap and wires to disperse some water. Sometimes this is a 50/50 bet it will/won’t work.

What I have done for many years is spray ALL the electrical wiring and connections I can get at with an ignition spray. It contains silicone and seals out moisture.

Since I started using the stuff, I have never once had a vehicle die from wet electrical components.