hazelnuts: So I've spent the better part of this afternoon trying to get this working, in Glide or D3D at any resolution above 640x480 and I finally figured it out. Posting in case this helps anyone else.

So I installed both dgVoodoo and nGlide trying to get it to play nice. Nothing I did changed the ingame resolution however, until I found a file called OpenGLid.ini in the Interstate 76 folder. Googling it told me it's the Glide wrapper GOG used, and it was blocking any of the newer glide wrappers I tried. I downloaded OpenGlide and it uses 2 files, the OpenGLid ini file and Glide2x.dll. Even though the version of Glide2x I was using was the newest one from dgVoodoo the OpenGlide one blocks it somehow.

I changed both the OpenGLid.ini file and Glide2x.dll to .old. I'd also previously removed Glide.dll so the only glide dll file now is Glide3x.dll

Finally I right clicked i76.exe and sent a shortcut to the desktop, then added -glide to the end of the target field. Now it works at full resolution and it looks a million times better.

I also have nGlide 1.04 running so not sure which glide wrapper is actually working it right now. I'm also a little baked so hopefully this makes sense...

Cheers.

E: Oh yeah and I also deleted Glide2x.ovl...