It’s called Walker (1987). Directed by Alex Cox (Repo Man) and starring Ed Harris. Not currently streaming anywhere I know of, but if you can find it on DVD or something I highly recommend it. The less you know going in the better. :)

a worldbuilding game such as the quiet year, for the queen or microscope, hacked to set up a concise and thematic noir mystery inspired by fiction like Disco Elysium, The City and the City or The Nice Guys

That sounds amazing. I love the thought of a Nice Guys-inspired campaign setting.

Is the game you’d like to run also Lancer? That would be a wild coincidence.

Edit: Oops, nevermind, I just saw your other comment!

Electric Bastionland has been the RPG I most want to run ever since I bought it years ago.

After watching a surreal Acid Western (which started out deceptively straightforward and veered endearingly off the rails by the final act), I’m itching to run In The Light of the Setting Sun: Bonanza Edition. But I’m at the end of my current FIST: Ultra Edition campaign and don’t want to rush anything. :D