Having driven a couple of the open top cars in v1.9, I notice that the original sound is still being used.
windleft3, windleft and windright are the guilty files. Having browsed the 'secondary' folder I noticed there is a windrush_in file, which sounds very good.
Alternatively, I've uploaded a looped version of the file I found on freesound:
If that were to be used, credit should go to freesound's ERH.