Dealers always jack up prices..especially on a harder-to-find car like the Spec V. You might be able to get a better price at
CarsDirect.com . They deliver, finance, take care of the whole thing...for cheaper than a normal dealer.
A good downpayment is as much as you can muster. Otherwise, for the first couple years you own your car, you owe more than it's worth (they depreciate approx. $3000 as soon as you drive it off the lot). I.E.: If you get in a wreck (totalled) and insurance pays the car's value, you'll still have to make payments to the bank until the loan is paid in full. So ideally your down payment should cover depreciation.
Can't help you much on insurance, my car isn't really comparable to yours.