Good downpayment for a new car?

I am planning to buy a brand new Infiniti G35 car. This will be my first car in my life. The base price of the car is $33,000. I am not sure how much sales tax and other things will add up to. I am wondering what would be a good downpayment for this car. My credit score as of today is 604. It is pretty low and I am worried. I would greatly appreciate your kind responses.