Size

• The size of your deposit can vary. The seller should decide the amount he wants to hold the car you want to purchase. Some dealers will take as low as $100 for a deposit. Some require thousands.
  
  

Significance

• A deposit confirms you are a serious buyer, and proves to the seller you intend to purchase the car. Dealers often require a deposit if you don't take your car home the same day. Also, when you leave a deposit, the vehicle is either taken out of a dealer's inventory, or off the market by a private seller.
  
  

Warning

• Before leaving a deposit, make sure you discuss the terms of purchase and whether your deposit is refundable. You never know what circumstances can change, and if you leave a significant amount of money down, you can lose it. Make sure you get a receipt, and get proof in writing that your money will be returned if plans fall through.