I watch touring and formula racing almost every month for years in local race tracks, like Tarumã, Velopark and Guaporé. And yes, it's possible to hear a car getting out of the pit-lane from a kilometer away.
When they're coming, a slightly low, but constant, thin engine and gearbox sound, thanks to Doppler effect. When they pass, the loudest point, with ear hurting and all that stuff (depends on the exhaust position too). When they're going there's thicker sound, with perceptive reverberation from the ambient.
It's just music.
For LFS, a question of better dynamic sound emission. Some small fixes, I think, would greatly increase the sound experience.