Normally 60-65% cars are sold at auctions but have you wondered what happens to the unsold ones?
For buyers, it is possible to put in a negotiation on a car through the auction house to which they will reply to with the reserve price.
For sellers, it is possible to put your car through the same auction next week, to take it to another auction house or hope a buyer may be interested in negotiation.
Let me give you an example, if you try to purchase a Corolla for 300,000 yen and the car did not sell at 295,000 yen (you are the highest bidder). The minimum negotiation price starts from 30,000 yen on the top of the last bid price (295,000 yen) – 325,000 yen. However, this does not mean that you can buy the car at that price, just means you have the right to negotiate from that amount.
The owner may come back with the figure of 380,000 yen for example. If you accept the offer, your negotiation is successful. It is totally depends on the owner but often you can enter a counter offer of say 350,000 yen in this case. If either ones accept at some point, the purchase is sealed.
One thing I forgot to mention that the last bidder always gets first priority on the negotiation. If the first negotiation fails then it will move to the second. But the seller is not allowed to sell it to the 2nd negotiator for less than was offered by the first.