I was able to take a peak at the back of this HU, and boy was I surprised.

I was looking for something to connect my PPC to, so I could play MP3s using this HU. I was thinking that there would be RCA jacks or something... but NO. All I saw were
PINS, which I think requires a 16 pin and 20 pin connector.
I didn't know that HUs are that... not user friendly anymore?
I tried to search for this HUs manual on the net, but to no avail.