What's the newest map DVD that can be installed in the Gen 2 RX? Has anyone done it?

I'm looking at this map dvd on ebay.

 

2006 RX400h has the Gen 4 nav which may no longer be updated. I think i read 2015 is as new as you can officially go. You can put in a Gen 5 DVD and it will work. Just keep the Gen 4 DVD in case you replace your battery. When you reboot for the first time after a power loss, the system will want the original Gen 4 DVD once. You can then switch right back to the Gen 5 DVD.

 

OK that was easy...
Received the $10 new map disc today (version 30 for 2015). Popped out the old disc, popped in the new. Reset the search area to CA. Voila!