Is there a video available of the removal and re-installation of the display and radio unit of a right hand drive 2004 Prius for the installation of a mp3 aux input adapter?
This video shows how to do the installation without having to remove the head unit: youtubedotcom/watch?v=IwbctEwsoNE This video shows full removal of the head unit (which is unnecessary if you can fit your hands through the gap in the last video): youtubedotcom/watch?v=92QN5HWuAo0 (Sorry, I don't have the permissions to post links yet.)
I don't think it would make a difference. Try opening the air vent to the right of the head unit (which is on the left side of your steering wheel) like in the first video and check if you see the same thing—it's very simple to do. If it looks the same, then just continue to follow the instructions. Let me know whether or not it worked.