Public cars and private cars
A car is public by default: it has a page others can find and read. Set it to private in car settings and it disappears from everywhere except your own account.
A public car appears in Browse, in the model rooms and next to your name in chat, and it can receive comments.
A private car is yours alone. No page, no browse listing, no comments.
Even on a public car, some things are never shown: what you paid, your VIN and registration, and your documents unless you explicitly allow them.
You can switch a car between public and private at any time, as often as you like.