Except in areas where the air quality is so bad that the rain just ends up making your car dirtier :\
Some mining towns had problems where their smelter fumes when mixed with the rain created an acidic rain that stripped paint off of cars. There was daily wind monitoring used to help settle the insurance claims.
Raindrops are at least. Water vapor need consensation nuclei to form around to create a raindrop.
That's what cloud seeding is based on. They introduce particulates for the drops to form around and fall.
Nah man we had some Sahara sand blow through, covered everything in a big layer of yellow dust. The next day it rained and the dust combined with the rain made some sort of cement which is stuck to my car. On places where the water pooled, like at the edges of the mirrors and the door seals it's caked on good.
Haven't bothered to clean it tho, just get annoyed every time I see it. Maybe I will clean it this weekend (I won't)
Here it rained that, everything yellow, then I regretted not cleaning it, but after 4 days and many people already having cleaned theirs, it rained yet again full of yellow sands and made everything dirty again. I felt really successful.
One time during a particularly dry month, someone scribbled "wash me" on the tailgate of my truck
I scribbled "no" on the other side
It stayed partially visible for like 6 months
I live in South Carolina, the rain just turns the pollen into a runny streaky mess unless it's like a huge downpour lol
All rain is dirty, your car may be dirtier than the rain so the net is a cleaner car but it's not likely a clean car.
This says why better than I can: https://youtu.be/jPttPFSJl_k?si=Tt_wS_9Vx9Rizih8
Ahem. Salt. Nucleation.
I’ll get my coat.
Edit: You are clever and nerdy, cheers for teaching me something new today.
This is usually my go-to, but I've started washing my car by hand every 2 years or so whether it needs it or not.
Many of those puddles are likely so contaminated with road salt that they are more like a brine puddle.
I live in the PNW, this is legit my strategy
It can get pretty grubby during the summer months though