Here is my install in a 2001 Santa Fe:
http://www.riocar.org/modules.php?set_albumName=album39&op=modload&name=Photo_Gallery&file=index&include=view_album.php
I now have a 2002.5 Santa Fe, which I was also able to install the RIO. It has the same dash layout other than the electronic A/C controls.
I'm not aware of any dashboard changes in the 2003. I did have to dremel the sides a little bit because the RIO is a little wider than the opening.
I'll be posting pictures of the 2002.5 install shortly. The 2002.5 is a replacement for my 2001 due to a major mistake my dealer made during a routing servicing of my car. By the way, I love my Santa Fe, it is a great vehicle. All I can say is BEWARE of the Stockton, CA Hyundai dealer service department.