Ah, I saw a few teaser shots of the Z and was interested but not 100% sold. Went to the Houston Auto Show and I was 80% ready to buy that day, test drive was what made me buy it.
You should do what I did not do, finish paying off the car and then save up as much as you can. My previous car was paid for and I have money for a down payment, but if I waited to buy a 2010 I probably would have just paid cash in the end. Though I really have enjoyed my Z this past year.