Update: (the short details)
This turned out to be Sun Roof related.
The rear passenger hose had a restriction due to partial clogging.
My cell phone bore cam (
https://www.amazon.com/gp/product/B071HYRPND/) spotted the clog in the rear passenger line.
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More details:
A smaller bore cam would've made it farther down the line.
There was a small water pool in the spare tire well. Never found water like that, back there before. The towels I had back there are why there wasn't more.
My earlier testing weeks ago, opening the sunroof and pouring a cup of water down the trough didn't really reproduce the issue.
Water would immediately and rapidly exit from behind the bumper. I only saw water leave the trough if I poured what I thought was an excess of it. So paid the test little mind.
I could only reproduce the issue if I spent literally ten minutes watering my closed up car as if it were a lawn,
while it was parked in a specific angle.
I removed the clamp altogether and will wrap the line with layers of electrical tape to prevent abrasion damage.
The debris corresponded with the location of a clamp; the only visible clamp out of all the lines that was visibly pinching the hose.
It's a surprise because the pinch was very minor.
Blew out all four corners with compressed air; 150PSI using a blow-gun.
For additional measure, I used some pseudo-stiff telephone wire to snake-out all four lines.
Also ran a bunch of silicon lubricant down the lines. (will be pouring some lubricant in the trough from time-to-time)
I can hear
@M-Sport fan talk'n from hundreds of miles away. I'm keep'n my sun roof damnit. ๐
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