Not an impreza but I have a 2001 330ci and it came fitted with the factory cd headunit but it is the professional version which from what I can make out is rare as most left with the business edtion.

The issue is the front LCD screen has an intimitent fault where most of the time it lights up but no text. For the last few months I have been keeping an eye on buying a teplacemet professional edition and have seen one which is on eBay now for £250! What I was wondering was how easys is it to replace them with one from a working business unit which can be had for £80-100 as I have bought one but unlike the professional the sound quality is not as good and it doesn't support iPod etc

So could I do it myself or does anyone know where I could send it off to?