12 volt hot when ignition on

[malmed]

I need to tap into some power for my GPS.
I need it to only be on when they key is on.
What or where is a good place to tap into?
GPS is located right by the center AC vent on the dash...

 

[Archer04]

Tap into the radio power it only functions when ignition is in on position. And if your mounted right by from ac won't need a long electrical run to reach ti.