I have the 4500NEX and I could not find anyone with the disk image for my sd card. I was able to find the image for the 4400NEX model. I loaded it and installed in my unit. Long story short, my unit is working again except the touchscreen. I can still connect to bluetooth and control media with steering wheel controls but I cannot adjust any settings ( time, bass, treble etc). I am glad to have a working unit but it would be great to have all functions working. If anyone has the the image please share.