Dice Silverline in 04 Prius

My wife has an '04 Prius, and she was looking at getting an integration kit for her Iphone. We were looking at the Dice Silverline, but I couldn't find any info on how it would actually connect and work. I reviewed instructions, but they all showed later models of the Prius. She doesn't have a Sat or Aux button on her radio, so how would she select it? I wanted to be sure it was compatible before we actually purchased one.

 

Thanks, that was the information I was looking for. I had tried searching in the forums, but I think including "Silverline" in my searches caused that thread to be left out of the results.