Need some buying feedback

Arc

I just have some questions.
I'm buying a 2011 370z w/Sports Package from a dealership.

1. The dealer I'm buying from is ordering one since I can't find the exact model I'm looking for (at any dealership).
At first the internet sales person said he'd need $1,000 deposit. Later, he wanted $3,000 deposit.
Is a deposit really necessary for an order? If so, which amount is correct?
The sales person didn't know the difference between a 2010 and a 2011 model. I guess knowing their products is not one of their job requirements.

2. I won't be getting the 370z until late March/early April, so I requested a receipt of the $3,000 deposit they charged me on my credit card. It was just a receipt with no documentation about where my deposit was going to and no manager signature confirming the deal so I'm curious if they will just steal my money after 90 days have passed since all I have is a receipt and I don't know if I can file a claim for that money if they don't deliver.

3. I'm putting down $10,000 and financing the rest. My credit isn't the greatest since I haven't been using any credit for a while (2-3 years).
Has anyone here done something like this and how much was your financing? Or what is a good financing percentage for someone doing this?
I don't have any debt, and I still have a credit card I'm not using which has a limit of $7,000 on it.

I know where the dealership is and I've been to their location (to pick up the receipt). They've got very friendly people there, and I think they helped out a family in need last Christmas. It was a big story here locally.

Am I disclosing too much information here, am I too paranoid, let me know what you all think.

If there's any details I'm missing or questions I should ask, any help is appreciated.