iPhone 4 and car stereo

[sasul]

Hi. I`m new here. I`m looking for an answer. Here`s the question: I have car stereo head unit that plays dvd Pioneer AVH P3200BT. And I`m not able to play Youtube videos or anything I shoot on my iPhone on Pioneer screen. I`ve tried RCA cables and also that cables with USB port and 3,5mm jack on one side and the other side goes to iPhone but it won`t work.
My other issue is if there is any possibility to transfer what I see on iPhone to Pioneer screen. I mean can I somehow use iPhone`s GPS navigation on bigger screen of that Pioneers unit?

Thanks.