Can I use white vinegar on a ceramic coating?
Quick answer: Not for routine washing -- white vinegar is acidic and repeated use can dull the hydrophobic behaviour of a ceramic coating. For stubborn mineral water spots a weak dilution used sparingly, rinsed thoroughly, then followed with a coating-safe spray will do no real harm. A dedicated water-spot remover is still the better choice because it is formulated for the job.
You probably can use white vinegar on a ceramic coating to shift water spots, but we would not recommend it as a habit.
Vinegar is acidic, and a cured coating is reasonably acid-resistant. The only real reason to reach for it is to dissolve something mineral, such as hard-water deposits. The problem is that there are purpose-made water-spot removers designed for exactly this -- typically £10-£20, formulated to be safe on coated paint, and far more predictable than a kitchen cupboard workaround. They also do not leave the car smelling like a fish and chip shop.
If you live somewhere with hard water, spotting will keep coming back. A bottle of dedicated remover in a spray trigger is easier to reach for than mixing a dilution every time, and it comes with instructions for correct use.
If you do use vinegar, dilute it with water, do not let it dwell on the paint, rinse thoroughly afterwards, and do not use it during the early cure time after a fresh coating. Vinegar is a short-term fix for mineral spotting, not a maintenance strategy -- decent washing and drying habits reduce the need for any of it in the first place.
One side note: never use wire wool to attack hard-water spots. It should go without saying, but it happens.
For the broader "how to wash and look after a coated car" answer, see how to wash a car with a ceramic coating.