Detected file types

Core / graphics / sound

Magic / content	Ext	Description
`@(#)GT-PS`	`.ps`	Course / track model
`@(#)GT-CAR`	`.car`	Car model
`@(#)GT-CTEX`	`.tex`	Car texture set
`@(#)GT-SKY`	`.sky`	Skybox
`@(#)GT-ARC`	`.arc`	Nested GT-ARC
`@(#)USEDCAR`	`.usedcar`	Used-car data
`@(#)GTHTML`	`.gthtml`	GT HTML / menu script
`INST`	`.ins`	Sound instrument bank
`ENGN`	`.es`	Engine sound bank
`SEQG`	`.seq`	Sequence (music / timing)
`10 00 00 00`	`.tim`	PlayStation TIM texture
TIM pack (count + `.tim` names)	`.tpk`	Named TIM container
Mostly printable text	`.txt`	Message / string table
Filename lists	`.idx` / `.lst`	Asset name lists
Other	`.bin`	Unknown binary

Car / tuning part tables (mainly CARINF)

Magic	Ext
`@(#)SPEC`	`.spec`
`@(#)COLOR`	`.color`
`@(#)EQUIP`	`.equip`
`@(#)TIRE` / `TIRECMP` / `TIRESIZ`	`.tire` / `.tirecmp` / `.tiresiz`
`@(#)BRAKE` / `BRKCTRL`	`.brake` / `.brkctrl`
`@(#)GEAR` / `CLUTCH` / `FLYWHEL`	`.gear` / `.clutch` / `.flywhel`
`@(#)SUSPENS` / `STABILZ`	`.suspens` / `.stabilz`
`@(#)TURBINE` / `NATUNE` / `MUFFLER` / …	matching

When a file list is loaded, list names override these fallback extensions.

TIM Pack format (COURSE / BG)

Offset  Size   Description
0x00    4      Number of TIMs (uint32 LE)
0x04    20×N   Directory:
                 16 bytes  Name (null-padded ASCII)
                  4 bytes  Offset of TIM data (uint32 LE)
…       …      TIM blobs at listed offsets

Archive kinds

Kind	Detection	Behaviour
`gtarc`	`@(#)GT-ARC`	Multi-file; GT-ZIP when `content_type = 0x8001`
`gtarc_compressed`	Mangled `@(#)GT-A` / `RC`	Whole-archive compression
`gtzip_raw`	No ARC header	Single GT-ZIP stream