Might make more sense, if you have a center console/arm rest in the front seat...maybe buy and mount an inverter to convert 12V to 110V and just plug in like normal? Just throwing things out there...lol.
My MG had a place in the centre cubby hole under the arm rest for a cigar lighter/12V socket but it was not an option I had selected when I bought the car. When MG went bust the local garage was selling off parts cheap and they had the 12V aux socket going for less than half price I bought it and installed it myself, had to remove the complete console carpet and glove box to get to the fuses. There was 2 ways of installing it, either through a relay that would shut the power off when you turned off the ignition or direct to the 12V bus and it would be powered all the time, I chose the latter and wired it to be on all the time, it is rated at 20A and not the 3A of a cigarette lighter.
My range rover has an Aux power outlet in the boot/trunk also rated at 20A and I use that to power my ham radio when I fit it to the car. in the glove box there is an Audio input and a USB socket that will play iPod or mp3 from a memory stick, wifey uses it to charge her phone in the car while I have an iPod/iPhone dock on the driver's side. The cigar lighters/aux power sockets can be programed to be either on all the time or go off with the ignition.