I have software version 7.1 in my 08 400h. I would love for my girlfriend to be able to enter new addresses while we're driving, but it seems that Lexus has changed/removed all the Nav overrides from this latest version.
I did, however, find the correct sequence to disable the seatbelt chime if anyone is interested. It took me a few tries to get it right, but it eventually worked. Now, I always buckle up. Just sometimes not in the first minute of pulling out of my driveway while I get situated. This was originally posted as instructions for an IS350 so it may work with other models. Good luck.
If anyone knows of any other system overrides (especially for 7.1) please post them.
a. Buckle your seatbelt.
1. Turn the key to the ON position, foot off the brake
2. Press the trip reset button couple of times until the ODO is displayed (not trip A or B ). Even if the ODO is displayed, cycle through until it displays again
3. Turn the ignition to the LOCK (OFF) position
4. Unbuckle the driver's seatbelt if it was buckled.
5. Turn the key to the ON position again. when the dash lights comes on, press and hold the trip reset button and count a slow 12-20 seconds.
6. While still holding the trip reset button, buckle the driver's side seatbelt.
7. The odometer display should read "b ON" or "b OFF". toggle the beep OFF with the trip reset.
8. The process should be completed when you unbuckle or turn the key off.