The exact same thing has happened to me - 2008 VW City Golf, just bought it and I get the USB ERROR 04 message when I try to play my ipod through the USB port. Has anyone figured out the solution???
I have a 2008 city golf, just bought the thing and as soon as i drove away and tried to plug my iPhone 4 in, the radio tried to read it then said USB error 04. I also tried a USB stick.
Is this a radio code problem or do i need a new USB port?