Renault Clio 1.2 Mk2 Boot 12V Socket

Hi, Recently replaced the 12v socket in the car but this is only on when the keys are in the ignition. I was thinking of having a 12V socket in the boot with a switch but not having to have the keys in the ignition, say for camping or just charging stuff and been able to leave it in the car!

Im guessing the ideal thing to do would be straight from the battery with a in line fuse, how would i go about feeding the wires to the boot?

Cheers

Roshurwill