adding an AUX jack to your stock car radio, 2 examples

I need to do this to the radio in my truck:

A Chrysler radio:
http://www.flickr.com/photos/cibomahto/2640696310/in/
set-72157606155081610/

a foreign brand auto:
http://blog.makezine.com/archive/2010/08/
adding_an_auxiliary_input_to_a_2004.html

Thank you Matt Metts for posting these. I have been contemplating
doing this for a while now and have looked for years to try to see if
anyone has done this. Will try to fit it into the project schedule
this year.