AUX in for Headrest DVDs

[HummerNewbie]

I am looking to do the same think but going the opposite way. I am looking to split the A/V feed that goes for the DS to the PS and feed it to the A/V inputs on my NAV unit. I had call the manufacture and they said they do not sell a cable to do this. I have not taken the time to look into it but was going to try to buy another cable and split it myself. Was in a higher end car audio shop yesterday for something else and asked about it. The guy said to come back next week and talk to a particular installer who might now how to do it. Post anything you find out and I will do the same