Radio Shack, Best Buy or look them up online.
Simply, eliminate the electrical noise and hum caused by ground loops. These problems typically occur when multiple components receive power from different locations. This isolator solves that problem by providing ground path isolation between components while maintaining full frequency response.
I have mine connected on the back side of the radio between the radio and the speaker wires. For the Magnadyne get one with RCA connectors.
The problem with the one from Radio Shack is it works fine, but you will also need connectors to change male to female (if I remember correctly) in line with the unit and the radio. Others you can order come with the correct connectors.
I would pull the radio to see which connections I need.
This should take care of the radio hum, not sure about the ipod.
I don't have that problem with my iPod
Here is a link to Best Buy which has the type with the proper connectors.
Metra Ground Loop Isolator TCGLI - Best Buy
link to connecters if needed (much cheaper than Radio Shack).