NFS Underground 2 and Most Wanted AI Mod: A Talking Crew Chief

The Black Box era of Need for Speed still has a huge modding scene: car packs, widescreen fixes, ExtraOptions, entire career overhauls. What neither game has is someone to talk to between races. An NFS Underground 2 or Most Wanted AI mod can add that: a crew chief who knows your car, reads the race as it happens and answers back. Neocortex supplies the AI character, its voice, quizzes and on-device voice commands, and your ASI plugin connects them to the game.

Screenshot: Need for Speed: Underground 2 © Electronic Arts

What you could build with Neocortex in NFS Underground 2 and Most Wanted

A crew chief who watches your race

Give the player an original crew chief character with a personality: a calm ex-drifter, or a loud tuner who lives in the garage. Your plugin sends race events with each message: position, gap to the leader, nitrous left, a wall hit on the last corner, a perfect launch. After the race the player asks "what did I do wrong?" and gets an answer about that race, in character, with an emotion tag you can use for tone. In Most Wanted the same character can work the police scanner side: "heat level 4, they have a helicopter on you, take the tunnel". Actions let the chief do more than talk, for example { "name": "SUGGEST_TUNE", "targetId": "gearing" } to open the right tuning screen.

Voice commands in the garage and on the road

With Neocortex Voice Commands the player keeps both hands on the wheel or pad. "How much nitrous do I have?", "open the map", "take me to the garage", "show my best lap": your plugin receives the matched command and runs it, or hands it to the crew chief for a spoken answer. The command set is designed as actors ("crew chief"), actions ("show", "check", "open") and objects ("nitrous", "map", "garage"), and players can phrase things naturally.

A tuning trivia quiz in the safehouse

Between races, the crew chief runs a quiz: tuning, car culture and racing trivia, built as a question set in the Neocortex dashboard. The quiz engine (Team plan) handles questions, scoring and a leaderboard, and the player answers out loud through speech-to-text. A perfect score could even earn a reward through your own mod logic.

How NFS Underground 2 and Most Wanted modding works

Both games are 32-bit Direct3D 9 titles, and their modding scene runs on native ASI plugins and data editors:

• Ultimate ASI Loader by ThirteenAG loads .asi plugins into the game process. Every code mod below depends on it.
• ThirteenAG's widescreen fixes for Most Wanted and Underground 2, part of the actively maintained Widescreen Fixes Pack, make the games usable on modern displays.
• ExtraOptions for Most Wanted and Underground 2 by the ExOptsTeam are ASI script mods that add a long list of gameplay and quality-of-life options. They are also a good reference for how a plugin hooks these games.
• Binary edits the games' binary data files (.BIN, .BUN, .LZC): cars, textures, strings.
• VltEd, the community editor for Most Wanted's VLT attribute database, changes car performance and pursuit settings.

Data editors change content. Anything that talks, listens or calls the web is a C++ ASI plugin. The plugin runs inside the game, reads race and career state through community-documented memory addresses and hooks, makes HTTPS requests with WinHTTP or libcurl on a worker thread, draws subtitles through a Direct3D 9 hook or an overlay library, and plays voice audio with the Windows audio APIs.

Screenshot: Need for Speed: Underground 2 © Electronic Arts

How Neocortex fits in

• Dialogue: the plugin reads game state, sends it with the player's line to a Neocortex character (/v3/chat), shows the reply as subtitles, plays the voice from /v3/audio/generate or /v3/audio/stream, and runs the actions the character returns.
• Conversation Flows: a flow can steer a longer exchange, like a pre-race briefing for a rival, and return checkpoint keywords (flowState) the plugin reacts to.
• Quizzes: the quiz engine runs the safehouse trivia through /v3/quiz, including scoring and leaderboard.
• Voice commands: on-device voice commands turn spoken phrases into game actions without a cloud round trip. The plugin uses the Neocortex Voice Commands library on the player's machine. Push-to-talk or always listening, in multiple languages.

The chat request after a race, in plugin terms:

// Build the /v3/chat body when the race ends (g_sessionId starts empty).
std::string body = R"({
  "characterIds": ["CREW_CHIEF_ID"],
  "message": "How did I do?",
  "playerId": "player-1",
  "sessionId": ")" + g_sessionId + R"(",
  "events": [{ "priority": 1, "content": "Finished 2nd, lost 1.3s in the last hairpin, nitrous empty" }]
})";
// POST https://api.neocortex.link/v3/chat on a worker thread (WinHTTP or libcurl)
// Headers: Content-Type: application/json, x-api-key: <key from the plugin's .ini>
// Reply: messages[0].lines[] -> subtitles + emotion, actions[] -> game code, keep sessionId

Getting started

1. Set up the game with Ultimate ASI Loader and the widescreen fix, and ExtraOptions if you use it.
2. Design your crew chief in the Neocortex visual editor: personality, emotions, knowledge about cars and tuning, voice. Add a quiz or a voice command set. Test it in the browser for free.
3. Create a C++ ASI plugin that reads the race data you need and shows text on screen.
4. Connect to the API from a worker thread and play the returned audio.
5. Read the API key from an .ini file each player fills in with their own key.
6. Test in single-player career and quick races.

Voice Commands is a licensed SDK: contact us for a Voice Commands license.

Mod policy and fair play

Keep the mod single-player and non-commercial, follow EA's user agreement for the game, and do not redistribute EA's game files: ship only your plugin and its config. Each player uses their own Neocortex API key, and nothing in the mod should give anyone an edge in online play or community leaderboards.

The same ASI approach powers our GTA San Andreas and Vice City AI NPC mod guide. For the voice side, read about on-device voice commands for game mods, or see how Neocortex compares on our comparison page.

Tool versions and links checked October 2026. Modding tools change often; check each project's page for the latest release.

Frequently Asked Questions