@@mgng1891 摘一個網上的說明: How much cash can I use to buy a car? Spend What You Can Afford However, under federal law, the dealer must tell the IRS any amount of cash that exceeds $10,000. This law requires your name, address, etc. It's lots of paperwork. Just remember, dealers prefer a cashier's check for any amount exceeding $10,000 if you're planning to use some cash.