I have a 2004 Fabia 6Y.  The car came without a radio and has never had a radio in it.  The car does however have the necessary wiring and speakers for a radio.

A friend of mine says he can get a used Skoda Symphony Radio from a 2003 model Fabia.

Is there any reason why the radio from a 2003 wouldn't work in a 2004?

I've considered getting a radio for the car in the past, and as I recall, many after-market radios (for instance from JVC or Blaupunkt) were described as being for either a 2003 model Fabia or earlier, or a 2004 model Fabia or later.

Any thoughts/first hand experience on this?

Will fit no problem if you get the code with it.