I am not sure what you're asking. Down payment is money you have set aside for your car. We do not have the slightest clue how much money you have saved up for your Z. If you're asking for an estimate, then i'll give you one. If you have good credit score and able to get a 3.99% financing then with 12K down on a 33K base with sports, you'll pay less than $400/month.
Here's a payment calculator
Car Payment Estimates from carmax.com