What is the ruling on the "deposit" between the seller and the buyer?

Question:
In car sales showrooms, the owner of the showroom resorts to taking a deposit from the buyer who has settled on the price of the car. If the buyer then decides against buying the car, the showroom owner keeps the deposit. What is the ruling on this?

Answer:
This requires a detailed explanation:
If an agreement is reached between him and the car owner on a price, and he says to him: "The deposit is one thousand riyals, and give me three days, or four days, or five days to consult and consider. If I come to you and take it, I will pay the rest of the price; otherwise, the deposit is yours," there is scholarly disagreement on this, and the correct view is that it is valid, and he is entitled to the deposit, because he wasted his time.
As for anything other than that, the deposit is not valid; it is part of the price. He either buys it or returns it to him, unless they agree on this. If they agree and he says: "Give me a few days to look into my matter and seek guidance from Allah. If I come to you and buy it, it is part of the price; otherwise, it is yours," then there is no harm, for Muslims are bound by their conditions.