The first step is to stay calm and not negotiate under pressure. A parent can make it clear that love is not measured by money, and that a car will not be bought simply because of an ultimatum.
Instead, the conversation should focus on what the car really represents: freedom, convenience, status, or a real need for school or work. From there, both sides can discuss realistic options like saving money, buying a used car, sharing costs, or finding alternative transportation.
If the child still chooses to move out, that must be treated as an adult decision, not something driven by guilt. The parent’s role is to stay connected while allowing consequences to teach responsibility, because maturity is earned through choices, respect, and accountability.