I paid a deposit for buying a car. Can I get a refund if the 4S shop doesn't have a car?

If it is clearly a deposit, the party paying the deposit has no right to demand a refund.

Article 89 of the General Principles of the Civil Law In accordance with the provisions of the law or the agreement of the parties, the performance of debts may be guaranteed in the following ways:

One party may pay the deposit to the other party within the scope prescribed by law. After the debtor performs the debt, the deposit shall be used as the price or recovered. If the party paying the deposit fails to perform the debt, it has no right to demand the return of the deposit; If the party accepting the deposit fails to perform the debt, it shall return the deposit twice.

Laws and regulations:

Deposit, according to the relevant provisions of China's current laws, does not have the nature of deposit, belongs to unilateral behavior, and does not have obvious guarantee nature. If the party paying the deposit claims the right of deposit, the people's court will not support it. In general, the deposit is regarded as an advance payment.