Best circuit to tap into for key on/accessory power for dashcam?

[mud]

I went to install a dash cam today and just realized both the cigar / cigarette lighter (left of the radio) and aux 12 V power (right of the radio) are both on all the time. Dash cam uses a USB (5V) plug into the cigarette lighter that's supposed to turn on when you turn the key on, and turn off when the key is off.

Is there a preferred circuit with easy access that I can tap into to add another cigarette lighter type socket? Low amperage is ok, as I'll never use an actual cigarette lighter.

 

[SenorNoob]

IDK about amperage, but the radio switched power would probably be easiest.

 

[lil_Blue_Ford]

Could use the radio switched power to trip a relay to have a key on power source, be easy enough to do and you wouldn’t have to worry about drawing too much power from an existing circuit.