I ask for an "out the door price" and negotiate on that. If I'm buying a fairly common car, like a Toyota Camry, then this is very easy to do across dealerships. I make it clear that I'm paying cash.
That's money they can flip immediately towards the purchase of another car.
* This won't work well for cars with limited stock. If a model/trim is leaving as fast as it's coming in they will prefer to give it to someone with dealership financing.
* If buying new make sure to be very clear to a dealership if you are calling from out of state.
I'm sure it's different for different dealers. I wasn't talking about anything too limited edition but mass market models that dealerships cannot seem to keep in stock. The thing were supply is just a little behind demand. We've seen a lot of that in the last 3 years, and it's still around for some make/models.
That's money they can flip immediately towards the purchase of another car.