Only on the front ?
I’ll bet you’re right that someone spilled acid on yor car…in effect.
While following some other vehicle in the recent past , did you ever get sprayed and all you did was run the wipers once or twice or think nothing of it ?
I got some spray from a semi load once. Some oily substance that would not come off for months…not with car wash, Windex or Dawn.
Well, it ‘washed’ and It looked clean , but every time it rained you could see the water spots peek through all the dots.