Where is the navigation DVD located in a 2006 Lexus IS 350?

There is a DVD drive behind the digital clock. There are pin tools to aid in removal of the clock panel that came in the toolkit in the trunk.

^Specifically, the tool is hiding within the "spine" of the toolkit as well. One could easily miss it.

Once you remove the clock face plate and have access to the NAV DVD changer, what are the steps, after you turn on the ignition, to eject the old NAV DVD and replace it with the updated NAV DVD? All I know is that you depress the Map Info button. But what do you do after that? By the way you do not necessarily need a flat head screw driver to remove the face plate. You can use two 30mm plastic suction cups with metal ringlets attached to them.

I have no problem getting the clock face off with nothing but the pin tools from the toolkit. On the info screen with the current map version, you should see the DVD eject button on the touchscreen. Push it to eject the old disc, and then insert the new one. If the new disc is the same version or newer than the one that was there previously, it will load automatically. (If you need to go back to an older version than the map disc you were using previously, I believe you need to pull and reconnect the battery or fuse before inserting it, but that's not something I've ever needed to do)