Now I have investigated myself. I tried different audio settings, also changed the soundcard options, no change.
Then I had a deeper look - or a closer ear - to the car models.
In two models I have downloaded from CarPark (F3, and cappucino hot rod), especially those "body" sounds are mostly empty.
After overwriting the bad sounds with the working sounds, e.g. copy loop_10004Rpm_throttle_engine.wav to loop_10004Rpm_throttle_body.wav, the sound is back with no exception.
Apparently Stadium is taking only the "body" sounds!?
As this is already in discussion in
another thread since a while, and Nadeo is also active there, lets see there then
