IMHO the best way to do this is by putting another 'layer' on top of the mod.
This will prevent you from altering the mod original files and it will be easy to revert your changes.
To do this you'll need to do the following.
In your cars folder create a new folder and call it MyCar (or any other name of course, but in this example I will simply stick to MyCar)
In there you should place the .gp4 meshes of your car and the textures. The names of the meshes are
not important, so no need to rename them.
Now in your cars folder (not the MyCar folder) create new ini file and put this in
[Config]
Dir8=MyCar
The '8' in Dir is the slotnumber. You can use any number from 1 to 11 of course.
Now all there's left to do is to tell CSM to process your new ini. You can do this by altering the .csm file of the mod and append the 'Cars' key
For instance there might be something in there like:
Cars =Cars\Default.ini
Then simply change it to
Cars =Cars\Default.ini,Cars\MyCar.ini
This tells CSM to first process the Default.ini and override it with MyCar.ini.
If the line is much more complex it shouldn't matter. Simply append it with a comma and your new ini.
This way you can simply revert by snapping off the last bit again.
You can do the same trick with just about anything.
To put your name in the mod, I'd use the custom profile feature.
Simply create a profile in Extra->Profiles matching the helmet shape of the mod and then enable it by right clicking the mod and select 'Use custom profile->your profile"
This should work on any mod that needs to build a wad file.
I'd rather have a bottle in front of me than a frontal lobotomy