This site allegedly gives you a ball park figure of what other people in your area are paying for the car you want:

https://www.edmunds.com/tmv.html

YMMV
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What I've done the last few times is print out results from cars matching what I want on cars.com. I take a couple of those to a local dealer and ask if they'll match the price so I don't have to go through the hassle of having the car shipped to me. As long as they were close to the number, I bought locally. None of them put up much of a fight so I'm probably still overpaying a bit.

Best,