Marking a car as sold
A sold car keeps its full history in your account and is shown as sold. Nothing is deleted, and your costs stay in your own figures.
Open the car's settings and mark it as sold, with the date and, if you like, the sale price.
Sold cars move below your current cars on the dashboard and are excluded from things that only concern cars you drive, such as which car appears next to your name in chat.
If the buyer is joining Elferlog, hand the car over instead — that moves the documented history to them while keeping your private figures to yourself.