Where is this water coming from? Rust on rear cross members.

[chrisarnt]

It seems like the rust on my rear crossmembers gets wet when it rains, even though I haven't driven.
I have rust in the same spots on both sides. I cleaned and prepped the areas for rust bullet friday night and let dry over night. It rained over night and the areas are soaked in the morning.
It seems like this is a very common rust area in these cars. I know people say these things get beat up with rocks snow and salt, but I'm not buying that when the car hasn't moved
So, it leads me to believe that there is water coming from some and draining into/onto the rear cross members.

What are the likely places?
I tried spraying water on the back window and side window. The side window dripped down the fender and into the hole on the right.

[Mike Fisher]

Leaking at your warped moonroof and running downhill in the roof? Tear out your headliner/interior so you can See what is happening.
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69 FI/AT square Daily Driver
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'68 Karmann Ghia sold

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[chrisarnt]

[VintageVulture]

Its coming from the years of wet roads and condensation seeping into the poorly rust inhibited panels that VW produced.
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[beetlenut]

Since all the grit and sand from the rear wheel is constantly blasting that area as it comes off the rotating wheel, coupled with the fact that the cracked undercoating is always holding moisture against the metal in that area, it really never stood a chance! I've replaced both those areas, and also the rear of the front wheel-wells that also have the same thing going on.
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scrapyards are for quitters
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[chrisarnt]

[oldmanmark]

You live in New Jersey. Winter, summer, hot, cold rain, snow, salt, condensation, age. Plus the rear wheel are thowing rocks at it.
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its all up to you and me to make it better...

[chrisarnt]

Actually, now that sealed up the rusted out ends of the panels that terminate just in front of the rear wheel there is significant less water in the car. Just a few drips from the moon roof.