Auto Motor und Sport actually reviewed all these three navigation systems. I have the scanned articles somewhere but I have not translated them yet.

Thing about the Lexus system is that sure, it has touchscreen, but it won't allow you to "use the system" while the car is in motion. This means that if you're in France heading towards Paris and all of a sudden you want to go to Amsterdam, you need to pull over, stop the car and then you can access the navigation system.

Is this true?