About to purchase a Prius 4

I live in southern New Hampshire and we are just about (in a few days) to go to our local dealership to start negotiations on a new Prius 4.

My questions:
1) I know I can get the invoice price on Edmunds.com. What are people's experience regarding purchase price? Since I see that the local Prius inventory at 4 dealerships in my area totals over 100 cars, plus the price of gas has been coming down, it seems that I should be in the driver's seat for negotiations. Can I expect to pay invoice, close to it, above/below?

2) Are dealers typically adding on certain "options"? For example, my local dealership automatically adds floor mats (which is ok), but they also add those wheel locks for approx. $65. Are people seeing this "automatic" add-ons?

3) Shouldn't expect a "deal" since it is almost at the end of the model year?

I'd basically like the Prius 4 as it comes; with no additional options, no sunroof, nav, etc. Any suggestions based on your experiences?
Thanks in advance,
Steve