I gave my friend (who has a 99 EX) my 6 disc in dash CD changer from my 02 EX since I bought a new head unit. It's a direct swap and is fairly easy to do. The 01-02 head units sound a little bit better than the 98-00 because the 01-02's deliver a bit more power. I forget how many watts each puts out though.. the difference in sound quality is slightly noticable. I'm not sure if your steering wheel mounted controls would work with the 98 head unit since I've never really heard of a 6 disc cd changer to 1 disc cd changer swap.
