Don't be afraid to walk. Don't settle for something, get what you want.
If they don't have it in lot they can build it for you.
Tread lightly for at least 1% below invoice.
Start there and then haggle with them.
I got multiple dealers bidding against each other and saved close to 4,000 on mine.
Take your time and don't rush. If it is new, it can always be built even if your dream vehicle is on the lot now and someone else buys it, you can build another!
Know what you want before you go and about the price you are willing to pay, don't let them talk you into something else.