Negotiating interest rate on a new vehicle

Hi all,

I am planning on purchasing a new vehicle this week. The dealer has an advertised 5.5% interest rate on the term length I am looking for. I have an 800 credit score. I have two questions.

1. Can I negotiate the 5.5% interest rate down?

2. If I can negotiate on this rate, do I want to use that as part of the price negotation, or save it for after we've got to a number I am comfortable with? Ie do I want to save it for the end of the deal or can I mention it if they aren't budging on the number I am looking to achieve?

Any and all advice is appreciated here. This will be my first ever new car purchase and I'd love any tips.

Thank you.