Hi,
I know there was a 3dsmax plug-in to edit the BL4 of the circuits or cars.
Is it possible to edit them with Blender 2.49?
I don't think I would be able to do something nice but I may modify meshes a bit, see the polygon count ... out of curiosity

Sorry for the late reply.

Yes, Sik wrote a 3ds Max plugin that only works on ancient 3ds Max versions compatible up to Win2k only.
I also wrote a Blender add-on to at least view tracks and cars, and export new versions of the latter (to some extent for now).
You may wanna check out my Pod discord for the links and discussion! https://discord.gg/zJ9bWGkDvT