At the end of the movie, Verbal Kint's limp disappears as he gets into 'Kobayashi's' car and drives away. If you were to add an Easter egg to the film, what would you shoot? Would it be Detective Kujan's despairing face, or 'Keyser Söze' revealing a completely new and different expression in the car?

Ha, this question is so interesting! Every time I discuss The Usual Suspects with friends, this exact point comes up. That ending is one of the best in film history. Adding a post-credits scene to it is like drawing a mustache on the Mona Lisa – incredibly risky, but if done well, it could be incredibly satisfying.

Let's first talk about the two options you mentioned, and then I'll share my thoughts.

First, let's discuss your two choices

1. Detective Kujan's Desperate Face

Effect: This choice is very safe. The last we see of him is his coffee cup dropping, his face a picture of shock and sudden realization. If the post-credits scene gave him another close-up – maybe him rushing out of the police station, staring at the empty street, or punching a bulletin board, sending the board covered with "Kobayashi" and "Redfoot" flying... this would amplify his frustration and despair to the max.
Feeling: This feels more like an "extended ending" than a true "post-credits scene." It reinforces the emotion we already know, but provides no new information. It's like a dish that's already salty, and you add another spoonful of salt – the flavor intensifies, but it's still the same taste. For the audience, the impact might not match the power of the film's original, abrupt ending.

2. "Keyser Söze" Revealing a Completely New Expression in the Car

Effect: This choice is much bolder and more interesting. At the film's end, he regains his normal gait, gets in the car, his expression cold, triumphant, utterly in control. What if, in the post-credits scene, he suddenly showed a completely different expression?
- For example, a weary or even sorrowful expression? This would instantly subvert his image. Could there be unspeakable reasons behind everything he did? Could the "Keyser Söze" identity itself be a curse and a burden? This would transform the character from a pure "demon" into a complex "tragic figure."
- For example, a fearful expression? Who is he afraid of? Is Kobayashi in the car the real mastermind? Or is he just a pawn in a larger organization? This twist upon a twist would be very thrilling, but carries enormous risk – it could destabilize the entire foundation of the story.
Feeling: This choice offers huge imaginative potential but is also easy to "mess up." The charm of The Usual Suspects lies in Keyser Söze's mythical, purely evil image. Giving him a humanizing expression might weaken his terror as an "urban legend," pulling him down from his pedestal.

If I were directing, I'd choose a third path

My idea is not to alter a single frame of the ending, but to add a completely new scene – a true "post-credits scene" that sends another chill down the audience's spine as they leave the theater.

My post-credits scene would be this:

[Scene] Screen fades to black. A subtitle appears: "Six Months Later. Buenos Aires."

[Visual] A rundown, exotic-looking police station. An Argentine detective, looking exhausted, interrogates a seemingly meek local merchant. The merchant is implicated in a docks smuggling case and is stammering his defense, telling a complex, bizarre story filled with strange names and places.

The detective looks confused, rubbing his temples.

The camera slowly, unobtrusively pulls out of the interrogation room, panning across the outer office area. We see the Japanese man who drove "Keyser Söze" away at the film's end – "Kobayashi" – sitting quietly on a bench, reading a local newspaper as if waiting for someone.

Finally, the camera stops in a corner of the office area. A man stands with his back to us, facing a case board plastered with photos, sticky notes, and newspaper clippings.

He slowly turns around.

It's Verbal Kint. Or rather, "Keyser Söze."

A cigarette dangles from his lips. His eyes scan the board intently, greedily taking in every name, every detail. Then, the corner of his mouth lifts in an almost imperceptible, satisfied smile.

[Screen fades to black. The End]

Why film it this way?

Preserves the perfection of the original ending: It happens entirely after the original story, as a separate fragment. It leaves the classic confrontation between Kujan and Keyser Söze intact.
Elevates "Myth" to "Modus Operandi": This scene reveals a more terrifying truth – Verbal Kint improvising his story while looking at the case board wasn't a one-time stroke of genius; it's his standard procedure! He's like a touring devil, arriving in a place, drawing "inspiration" from the local police station's case board to weave a new identity and a new set of lies, executing his criminal schemes, then vanishing without a trace.
Amplifies the terror of "Keyser Söze": He's no longer just a fugitive criminal; he becomes a "concept," a ghost who cannot be tracked or defined. His most dangerous trait isn't his cruelty, but his ability to pluck "reality" from thin air and spin it into "fiction." This scene tells us he's gone, but he could reappear at any moment, in any unassuming guise, in any corner of the world, to continue his "creative work."

I believe a post-credits scene like this is worthy of The Usual Suspects. It doesn't gild the lily; instead, just when the audience thinks the story is over, it drops a deeper, colder bombshell.