I am waiting for a lock pick that will help solve this problem in a convenient way. Should be here anyday.
Basically it is a harness that plugs between the vehicle and the nav. There is a button that you mount in one of the blank switches on the dash. When you want to unlock it, you push the button. You have 5 minutes to do your thing, then it locks again, or you can push the button again and it locks and reacquires your position.
The penalty is that the position on the map does not update until it locks again. Basically it stops the pulses telling it the truck is moving. Stupid Nanny NAV does not believe the GPS signal and uses the speed pulses instead of GPS. It should not be a big deal since you putting in an address, but I'll have to live with it for a while before I decide if it is or is not effective.
Supposed to unlock video too, but I don't have that myself.
Another solution is the burn the disk hack, but that is a PITA to me. You can also enter an address by voice while moving. But even with all the STUPID prompts turned off, it is still a PITA.
Be patient and I will post results.
When I got my JD Power's survey I really blasted Toyota for that Nanny NAV, between the stinking lock, crummy voice recogniction prompts, the crappy routes it picks, and the $300 map updates, the $200 Garmin I used to have is far superior.
Maybe if we all keep telling the reviewers like it is they will eventually change.