Don't underestimate this. They can't push your hot buttons if they don't know what they are. No down payment. People are used to no money down or just trading-in. Unless you own your trade-in outright or have significant equity in it, you'll want to use at least some cash as a down payment.
Any amount is better than nothing.
Borrowing money is very expensive. Down payments will lower your monthly payments, save you money on interest and can sometimes earn you better rates on the money that you do borrow. Wind up 'upside down' . This is more of a situation that you find yourself in rather than a mistake, and it is VERY common. There are, however, things you can do to avoid finding yourself upside-down.