Hi Ryan,
Thank you for your inquiry.
For your 2006 GS 300 with ML, the correct NAV and DVD override is the NT3203US.
Link:
http://www.beatsonicusa.com/beat-son...ss-module.html
The cost is $220 MSRP shipped.
for your 2009 Lexus RX 350, you will need a different module: NT3712
product link:
http://www.beatsonicusa.com/beat-son...ss-module.html
For the 2008 LS 460, the same NT3203 module will work.
Please let me know if you have additional questions.
Thanks,
Eric