When modders make a new soundbanks for their cars, they usually just open Tatuus Formula Abarth FMOD project and replace original samples. It’s a good and simple way, but usually they forget about change GUIDs. And later Cars Manager will think that sound is taken from Tatuus Formula Abarth, but it’s not the biggest problem with that.
The biggest problem is (and you can check it anytime) that if you starts a race with two cars having same GUIDs, they will have same sound! They will be sharing soundbank of the car which was loaded first.
I’ve made a little video how you can easily make GUIDs in your soundbank unique. It’s only takes about 30 seconds (and, I’m sure, this time could be decreased in half):
So, please, update your GUIDs. As you can see, it’s a very easy operation which could solve some problems.