I have a 2010 Prius with keyless entry and start - you just need the key in your pocket or bag. It may sound a bit gimicky, but I really like it. No more hunting for the key, I just leave it in my ruck sack.
If the battery dies there is a hidden key in the fob that can be used to unlock the drivers door. To start the car you can hold the fob on the 'Start' button - there is an RFID chip inside which is read.
If the battery dies there is a hidden key in the fob that can be used to unlock the drivers door. To start the car you can hold the fob on the 'Start' button - there is an RFID chip inside which is read.