I think you have defined what I was thinking, IRL the sounds change due to the surface, as well as the amount of smoke generated by the skid/burnout etc.
As LFS doesn't have different grip for different surfaces that I know of, everything, apart from speed of drift, skid etc is a constant,.
if Scawen introduced a variable to the tyre skid generation or something to simulate greater or lesser levels of grip, but at this stage not actually affect the grip,( sort of a fill in till proper changing road surfaces and grip are introduced) perhaps on a random basis, I guess then we'd hear a different sound that is more realistic to racing