Despite having a carport, I still have frost forming all over my car, melting as it warms up throughout the day. I real hassle with a black car
I can see spots only with direct light when I breathe on it.
The temperatures have been fluctuating a lot in recent days. It seems rather hopeless to wash when it will all be back tomorrow, but it's supposed to be getting (and staying) colder again in a few days. How long can I let it sit before the spots become etched and require polishing to remove? It has a couple coats of Opti-Seal applied before winter (2-3 months ago) and it doesn't see a lot of sun.

The temperatures have been fluctuating a lot in recent days. It seems rather hopeless to wash when it will all be back tomorrow, but it's supposed to be getting (and staying) colder again in a few days. How long can I let it sit before the spots become etched and require polishing to remove? It has a couple coats of Opti-Seal applied before winter (2-3 months ago) and it doesn't see a lot of sun.