Got my new prius 2010 ..Navigation freezes !

Welcome aboard. If you read through this forum (or just use the handly little search), you will get your answers.

Yes the GPS system does have a lockout feature for when the car is in motion. It generally locks out a lot of functionality once you go above 6 mph. As you slow back down again, it unlocks around 3 mph to allow you to enter your requests again. This is a 'safety feature', though many here, including myself, would love a way to disable it.

The fuel gauge is generally pretty accurate, and is a pretty good indicator. That said, like many cars, a 'full tank' will register full for the last 10 percent or so of the gas tank, so it's possible that it was not all the filled to capacity, just enough to mark it full. (On analog gauges, it's like the needle moving way past FULL). For me, often I notice that I have to drive 50-80 miles to get the tank to mark that some fuel has been used, so this may be the same. Many folks here have reported (myself too), that as you get low on fuel, and the last indicator starts to flash indicating you are low, that you still have anothe 20-60 miles left after that point. But do not try to test it unless you drive near gas stations.

Finally, as for you battery question in the FOB, while I am certain that there is a lifespan on the battery in it, I know that even with the battery dead, you can hold the fob against the 'Start' button, and then start the car. Even when out of power, it still operates (but does not transmit).

Please let us know if you have any more questions, and welcome to the Prius!

 

To elaborate a little bit:
Certain features can be used while moving. For example, speed dials and the quick preset destinations (like Go Home and 1-6, IIRC). However, you can't type an address or a phone number, or do a search for a destination, or things like that. Some day a hack might come out to disable this, as it has for the Gen II Prius. But for now, you can at least use the buttons for your common destinations even while moving...

The gas gauge is about the same as any other car. The second-highest pip probably represents the smallest amount of fuel, though (it seems to disappear quickly, typically, I think).

And if your fob battery is dead, you can use the mechanical key to get in the driver's door, then hold the Toyota logo to the key and press the brake pedal, then the power button, and it'll turn on. If you try to turn it on and it doesn't detect the key, I think it'll show those instructions on the MFD as well.

 

If you initiate the navigation input while stopped using voice commands, you can complete the entry while moving, i.e., while at a stop light, stop sign, or while traveling at a low rate of speed, press the voice button on the steering wheel and say destination. Then you can proceed to enter the address even after you started moving again. Once your home, enter your address as Home and from then on, you just have to press the voice button and say go home, this can be done at any speed.