This seems to be a rare game and I'm having trouble finding a download for testing purposes, just some suggestions though:

1: Have you configured _inmm.dll properly? Does it work with other games?
2: Have you tried ogg-winmm (the wrapper included with most GoG games)?
3: Have you tried the unpatched version using the first CD drive letter?
4: Have you checked CD audio volume is set at 100% in game settings?

1. I believe I have. The only game I ever used it on before was Sega Rally 2, and I haven't got to reinstalling that yet.
2. I don't have any GOG games so don't have this file.
3. Game is unpatched, installed on drive D with CD in E. I think this is the setup I have on my older XP machine where the music works.
4. Yes, it is, the fact it doesn't flicker continuously shows it's not playing.

http://hifi.iki.fi/carmageddon/wav-winmm.dll

There's a compiled version of wav-winmm (ogg/wav-winmm is a open source project GoG uses). Rename it to winmm.dll, place in game folder.

Then create a subfolder "Music" and place wav files of the music files there with naming scheme track01.wav , track02.wav ...

DelayWinMMCallback ACT flag also sounds interesting. I'm assuming you do not hear the CD drive seeking at track changes when it's _inmm.dll patched?

Oh, and when trying to patch with _inmm.dll, are you patching the right files? Which file(s) are you patching and what .exe and .dll files (.icd?) are there in the game directory?

_inmm.dll is patching the main game exe file (called something like racersDX7.exe I believe; there's no icd files). Once patched, the game moans about needing the .ini file when starting (if one is not present) and makes a racersDX7.org, so it looks like it's being patched properly. I tried making the .ini file both with CD tracks and MP3 route.

However I will try your GOG alternative later on. Mad Trax also has this music issue, so I'll see if it helps that too.

VirtuaIceMan wrote:

_inmm.dll is patching the main game exe file (called something like racersDX7.exe I believe; there's no icd files). Once patched, the game moans about needing the .ini file when starting (if one is not present) and makes a racersDX7.org, so it looks like it's being patched properly. I tried making the .ini file both with CD tracks and MP3 route.

Well, even if you patch the main exe, that might not be the file responsible for music playback. It might just call winmm.dll for other functions.

So please list all files in the directory or at the very least all .exe and .dll files (assuming there are any).

winmm.dll above with Music folder containing named wavs didn't work; the game's CD audio tester still caused the CD read head to move, so I don't think the game is calling winmm.dll. The DelayWinMMCallback flag doesn't do anything extra.

The game install contains:

1 Volume in drive D has no label.
2 Volume Serial Number is 1E75-A513
3
4 Directory of D:\Games\nascarracers
5
622/01/2015  23:46    <DIR>          .
722/01/2015  23:46    <DIR>          ..
821/01/2015  23:36    <DIR>          AI
921/01/2015  23:36    <DIR>          Audio
1021/01/2015  23:36    <DIR>          Fonts
1121/01/2015  23:36    <DIR>          FrontEnd
1222/09/2000  13:49         4,788,224 HSBR.exe
1327/09/2000  11:03           282,624 launch.exe
1422/01/2015  23:45           332,640 list.txt
1522/01/2015  23:46                 0 lost.txt
1621/01/2015  23:38    <DIR>          Models
1721/01/2015  23:36    <DIR>          movie
1822/09/2000  13:49             2,238 Nascar.ico
1927/09/2000  10:57           766,017 nascarDX7.exe
2022/01/2015  23:43                44 NascarRacers.cfg
2121/01/2015  23:36    <DIR>          Overlays
2222/09/2000  13:49            14,120 ReadMe.htm
2321/01/2015  23:36    <DIR>          Screens
24               8 File(s)      6,185,907 bytes
25              10 Dir(s)  2,871,309,234,176 bytes free

HSBR.exe is a Hasbro program to register the software with them, by the way.

FWIW that winmm.dll trick doesn't work with another Hasbro title either - Frogger

I was hoping it would use some other dll file for CDDA playback.

One last thing: have you tried patching it with _svfw32.dll ? It's an optional extra for _inmm.dll and from what I gather I think it must be used in conjunction with _inmm.dll.

FYI: It does not work with Mad Trax (unimplemented calls).