i do not do anything to doppler i just check how it sounds in pitch with the same angle in game than the real video and sounds about right.
If you are annoyed because form cokpit you can hear the outside engine on some part of the track it is because the kunos reveb zones.. you can go and turn reverb values down. in the audio sources in the track data folder, cause inside the car you shouldn't hear any reverb at all
you know, I have a musical trained hear. I know many things about sounds. I detect every changes in pitch. and a real engine doesn't have a difference in pitch other than an octave between the interior and the exterior sounds. your sounds are very realistic, but this is the only thing that bothers me. I don't want to be rude, because I respect your work. but I suggest that you make a version with the same pitch on both type of views. and the peoples will judge wich one is better