Hey everyone. I just joined here, and I drive an 06 IS250 w/ nav.
Well...I was able to make a fully-working backup copy of a Gen 5 8.1 nav DVD. Just letting you guys know that they are not copy-protected and can be backed up/copied using dual-layer DVDs. I'm going to get my hands on a 9.1 soon and hope that I can make a copy of that as well.
Anyways, just giving you guys a heads-up on this, and if anyone would like a copy, send me a PM. I can probably get the Gen 4 as well.