Probably better to depend on the OS security for this.

Maybe so, but iirc the iPhone pin-code is pretty easy to bypass.

Perhaps it's just me that's paranoid! :)

Oh well sure, more security is always better. :-)

I was just thinking that if they were able to reach email then the map app security isn't as much of a concern.

You can configure the lockscreen to require a fullblown passphrase if you think pins are too short.

Of course, but there have been security flaws in the past that allowed you to easily remove a pin or passphrase.

I'm just nervous about saving my "home" address. Your car has keys, but you're still advised not to save your home address under "Home" on your satnav. It's the same thing.

Hm, there are some provisions in the secure keychain that supposedly encrypt keychain data with the pin/passphrase. Wonder if those lockscreen bypass flaws affect that? (Google "kSecAttrAccessibleWhenUnlocked" for a start)

Presumably it is on your registration or do you not keep that in your car?

I do not keep that in my car.

UK law allows me to carry only the license part and leave the paper part at home. In the event that I should be required to produce it, I am allowed four days to take it to my local police station.

Exactly why I'm wary of this program although it looks like it's VERY useful.