First contact the person concerned by phone and ask to meet face to face in a public and safe place.
Go to the appointment with a friendly or family member for security.
Check that you are on
Car.gr and not on a fake website. The URL should always start with
https://www.car.gr.
Prefer payment in cash when meeting in person.
If you are paying online, make sure you are on the secure environment of your bank and not on a fake website.
Never share PIN or SMS codes with anyone, even if they appear friendly and willing to help you.