I have a 2003 RX300 and its annoyed me since I got it that I cant do
some operations on the NAV system while moving. It seems like a
random set of features are disabled but its not like they turned off
enough to make it totally non-distracting. And add that to having a
passenger that wants to use it in a totally safe way, the feature is
dumb. I'm looking into hardware hacks but in the meantime there's a
cool non-intrusive way to shut off that "safety feature":
When not moving, press menu, system option, then press top left
corner of the screen, bottom left corner, top left corner again,
bottom left corner again, then bottom right corner. This brings up a
special diag menu, press the override button and until you shut off
the car everything will always be enabled whether you're moving or
not. Sounds long but once you get used to it it goes fast. Seems to
work on most models of Lexus.
Its annoying that this hack can only be done when you're initially
not moving (i.e. if you start a long drive and then remember you want
to use it you have to stop first) but at least once you've done it
its good for the rest of the drive.