If this helps you any I'm a 23 year old married student. I've got very good credit according to the dealer and my banker. I don't have alot of credit mind you, I've just always been on time with bills, payments and such.
I paid 3000k down, and financed 16000 with my bank. At a 7% interest rate over 5 years my payments are 324 a month.
Insurance on this car is going to run me about 420 for six months. Thats compared to the 360 I've been paying for a 93 saturn sporst coupe. Not bad at all I say.
You can go to the Nissan site or
www.Saturn.com and use the affordiability calculator thingy to figure up monthly payments and such. It lets you configure the months of financing, the interst rate, purchase price, trade in value, and down payment in order to give you a ruff quote on payments.