For full cutscenes, also check sfx\scripted_speech.rpf and sfx\mission_audio.rpf . Some one-liners are scattered across multiple archives.
Many websites offer “cutscene audio fix” downloads that contain malware, adware, or simply renamed dummy files. Always verify sources. gta 4 cutscene audio files download install
Installing total conversion mods or high-definition texture packs can sometimes overwrite or corrupt the original .rpf audio containers. For full cutscenes, also check sfx\scripted_speech