The sounds itself sounds great however I have a different experience with it volume wise. I cranked the sounds responsible for the kerb sounds and am not getting the same results. I took a look at your sound settings and have tried them, but it seems like I am sacrificing engine sounds for road sounds. Even using the extension script, I feel like its not loud enough, plus also even if it does fixes it, it is a very tedious effort to add it to every single car you use. I think it would be great just to raise the volume of the sounds and let the user adjust the volume of it themselves to their liking.
This is the pack I was using before and its fine volume wise:
Can you retest out the volume comparing this, stock and yours to see if you need to increase the volume of your sounds. I will keep checking on my end to see if its on my side but I am pretty sure I am out of options.