If you have a Costco membership, I highly recommend you contact the Costco Auto program [1]. They pre-negotiate a discounted price with nearby dealer on your behalf.
In the end, I went round-robin with a few dealerships (taking one dealership's offer to another dealership and asking them to beat it), and wound up with a price around $1000 less than the Costco Auto price. I had to drive an hour to get the car, but that's no big deal in the long run.
So my two cents is that Costco Auto maybe hits a sweet spot between "don't want to negotiate" and "good price". But if you enjoy the thrill of the hunt, you can probably do better than the Costco Auto prices.
If it would - that typically is a great deal