This isn't an every case, but maybe just don't even bring it up until the end. Claim you want to get all the numbers settled, even if they're discussing payments and stuff, just keep an eye on the actual price of the vehicle (+ taxes, title, doc fees).
Then at the end you could just say, great, and say you'll be paying in cash. They might be miffed, that's their problem.
Some places still make you fill out a credit app for liability purposes, but I'm not entirely sure that's even necessary in actuality.
Now, that said, sometimes dealerships get kickbacks based on financing deals they acquire - so it may bake into the price they're offering. If that's the case we often just told people straight up and then gave them instructions on how to make principal-only payments. So you could feasibly do this to snag a great deal and then just pay it off immediately.
Another benefit for the latter is if it's 0% or close to, you could do it over 6-12 months that way if something insane happens you'd still have that cash just in case and your total interest outlay with the accelerated payments would be pretty negligible.
Sounds like bullshit.
Source: Farms near me have already lost people to deportation. People with no criminal record. People who paid more taxes than a lot of people I know. People who work hard.
Fuck this administration.