Can you post a photo of the actual NAV unit? I think you may have either an aftermarket one or one that is completely different than the one described in the manual you downloaded. Do you know what country your Insight was first sold in, or made for?
In the US, our NAV units do not play DVDs or any other video media. You have what looks like a left & right audio plug plus a composite video input adapter plugged in. To the right is what looks like a DVI input. (Also video)