If you have the arm rest with the standard plastic you will need to change it and run the lead to the back of the stereo to use it, you will also need to change the air vent pipe to a cd changer version rather than cooled compartment version. So a bit of work but nothing too taxing if you have a reasonable skill level and some patience.
If you do decide to go down that route I have just removed my ipod dock in place of a CD changer so if you want it you can have it for £40 I have the different ipod adapters and even the manual for it somewhere to go in the log book.