i dont have an ipod video cable, but i did mount the usb/3.5mm under my armrest:
i installed it this way for several reasons. if i ever get around to buying the 40 dollar video cable from pioneer, i can simply just plug it in there. if i dont ever buy it, i still have the 3.5mm accessible for when i want to use it with my phone or a passengers mp3 player/phone. also the usb doubles as a charger