I agree with you, most of the sounds from the interior sound terrible.
Even if the sound of the engine and transmission is fairly close to the original, the overall reception is poor, as if the mastering was not perfected.
In Dirt Rally 2.0 these sounds were juicy, even despite the considerable similarity between the cars.
In EA WRC to improve:
- Subaru Impreza 555 - too quiet engine (in reality the engine is very raspy)
- Subaru Impreza WRC 98 (the transmission howls more)
examples https://www.youtube.com/watch?v=8ChajB-7dV8&t=31s
https://www.youtube.com/watch?v=7oJLbICjK70
- Subaru Impreza WRC 2001 (More rough engine sound, the transmission drowns out the effect and is not howling enough)
https://www.youtube.com/watch?v=zhkj_r9Bdzk&t=333s
https://www.youtube.com/watch?v=rGtCYoBxp6Y&t=613s
- Ford Focus WRC 2001 (The same, castrated engine sound and not enough transmission howling)
https://www.youtube.com/watch?v=tBGzCdG3fhQ&t=180s
- Ford Focus WRC 2008 (same as above)
Xsara, C4, Fabia, Impreza 08, Evo VI and 206 WRC seems sounds ok. Super 1600, F2, Super 2000, WRC2 and Rally1 also good job