Hey, nice job! It's a little like my first holder I made some time ago.
Info on this one was at
http://home.comcast.net/~srgilbert1/Iriver/Iriver.html
I since redesigned because, #1 I got a new car, and #2 I hated taking it in and out of the case everytime I wanted to use it. The new design is also much simpler.
Info on this set up can be found through the link in my sig.......