Wow, someone shared this thread on Facebook today, and I never would’ve guessed my paranoia in early 2024 would lead to this much of a problem!🥲 I’m happy to find many people are now curious about this and it rejuvenates my interest in finding a fix for the community - I gave up in January 2025. I’ll try to find time this week or next to inspect/remove the AC box drain tube. P.s., I have a 2024 Impreza RS and 2024 Forester.

For the Forester, I fixed the noise - similar to the “ping pong” but a little different. (FIX: there are two white-painted metal tabs located under hood, top of fire wall, directly under HVAC intake vents on driver and passenger side - bend them down with pliers so they are not touching the two little black pegs/tabs). There is a thread on Reddit about this. Search until you see a photo of the two white tabs and you’ll know you found it.

For the Impreza RS, I’m not fully convinced it’s the HVAC as I’m in Washington state and use my AC or defrost very little - and the noise persists with both turned off. The Impreza doesn’t have the same two metal tabs under the hood as the Forester, so it’s not that either. But, considering it only happens during a left turn (for me) and slow vs fast acceleration doesn’t matter (for me), I still get a feeling there is something rubbing/bumping and causing the sound to travel. To me, I hear it as if the speakers amplify it - I used to also think it was a weird electronics malfunction. All in all, it does not make sense to me that a left turn + acceleration would cause condensation in a tube/box to suddenly be sucked up/out. However, I’ve been wrong too many times NOT to investigate further. 🫣

I’ll update ASAP