I reached out to maybe 7 or 8 dealers, had a couple that refused to provide a total itemized cost, and then got back 5 quotes that varied quite a bit (like $7500 on a $30k car).
Did one round of negotiation which ended up lowering the lowest price another thousand bucks or so and went with that dealership.
When I bought a truck in 2019, there was only one in my state that had the features that I wanted (I did not tell the dealer this). I tracked down the fleet/internet sales manager's email and emailed him asking what the Out-the-door price without incentives was on that VIN, then when it came time to do paperwork, I told them to apply incentive codes XXXXXX and YYYYYY. They tried to add on a dealer package for $1500 (I laughed when they explained it to me: nitrogen-filled tires, VIN etching on the windows, tint on the rear windows, and security lug nuts, I said we're breathing 70% nitrogen right now, and you can buy a VIN etching set online for $10), so I kept saying "no" until they asked if I could do $150 which was their cost, and I said yes to finish the deal.
I told the salesperson that I understand they have to make a profit, and I have no issue with that, that they probably made $1500 to $2000 after the manufacturer volume incentive, and he said they only made $800 off of me.
Absolutely brutal.