Best place to tap constant live in boot

[Evil Derboy]

Can anyone help?

I'm looking for the best place to tap into a constant live in the boot area. I've got an old iphone and thought I might as well use it as a tracker. So I'm looking to put a 12v socket in to charge it.

 

[bruce_miranda]

The battery. All the other power lines seem to run to the front to the power management module and controls everything including the 12V sockets.