First of all - rFactor applies it's own racegroove, that's defined by AIW and TDF files. Typically it uses racegroove.tga texture. You can make that racegroove.tga texture wery weak so it won't come on top of racing line you have made with shaders. Perhaps that's what you're seeing.
My editor will of course not affect standard racegroove in rFactor - it doesn't export AIW files nor TDF files, so you have to weaken/remove that racing groove yourself.
To make sure that your materials got exported, try changing one of road materials - put some weird testure on it and see if it gets exported.
If not, then it muse be something related to pathes set in .scn file or it could be that some other GMT files, that you haven't added to your project contain materials with the same name as road and they get loaded by rFactor first. rFactor always takes material from the first GMT file it's been found in.
Also - try full export option if you haven't allready.
aiwMap.tga contains strength of race groove across lap - if you look at this texture then you will see one long line travelling left/right and slowly up/down - this way it's one continous line and represents one lap. If you paint some vertical line on it, you will see it on racetrack - repeated 64 times in regular distances.
And of course you don't need to pack anything into .mas files for testing
What I usually do is this:
1. Create 'SrcFiles' folder and unpack all contents of .mas files there (textures and GMT files)
2. Create 'MAS' folder
3. Create project and set 'SrcFiles' folder as texture path
4. Add all GMT files from that folder to project, except for SKY.GMT (or any GMT that contains sky)
5. Set 'MAS' folder as my export folder
6. Remove references to .mas files from .scn file
7. Add reference to 'MAS' folder to .scn file and reference to 'SrcFiles' folder (must be below reference to MAS folder)
Now I can just make changes and perform full export.
When packing, I just take everything from 'SrcFiles' folder and overwrite it with what's in 'MAS' folder.