to think that this is not good car-washing weather?

[PurpleStorm]

It's been snowing here today, quite heavily this morning, with freezing conditions and light snow forecast for overnight and tomorrow.

I've just looked out the window, and our neighbours across the road are washing their car. Their driveway slopes towards their garage, so if all the water they're throwing around freezes into a sheet of ice (they've cleared the snow off their drive), it's not really going to be a problem for anyone but them - but still. And it's going to be dark in under an hour.

AIBU to think that my neighbours are being daft to wash their car now?

Yanbu.

Although I don't think any weather is good for car washing

No-one washes their car outside here when it's -20. Your door seals freeze and that's you not getting in it until March or April.

We have indoor car washes though. You drive into a bay inside. It has everything you might need. You pay by the minute, so it's up to you how clean and shiny you want it.

Some people just don't bother. It's too cold for road salt here so corrosion is less of an issue.