Is there a car charger for the 2023 MacBook Air?

Not directly from Apple, no.

But there are many third party alternatives.

You just need a USB-C charger with enough power. The MagSafe Cable is removable from the Mac's charger itself, and can be plugged into a car port charger with enough power directly.

click here ➜ USB-C Car Charger for Mac / Laptop - Amazon.com

I was researching for a car charger for an employee and the best option I came across was from Satechi (I think this is the one I recommended):

https://satechi.net/products/72w-type-c-pd-car-charger-adapter?variant=29681251582040

Satechi has made products for a long time so I would trust them more than other third party unknown brands many of which are cheap Chinese clones which may have taken some shortcuts with the electronic circuitry. Some of them may be perfectly fine, but knowing which ones is tricky since product reviews these days cannot be trusted.