12V Accessory Plug In Centre Console Convert To Permanently Live?

Has anyone tried (or know if its even possible?) to rewire the 12V accessory socket (what was the cigarette lighter socket to us oldies!) in the centre console on a 2013 1.25 Zetec to make it permanently live (as it stands at the moment, its only live when the ignition is 'ON' or the engine is running) like it was as standard on my old 1999 Mk5 1.4 Zetec?

The reason being is that occasionally I want to use the socket to plug in a charger to charge my mp3 player or mobile phone overnight in the car while its sat in my workplace carpark (its secure) with the ignition off and the car locked, while I do a nightshift. I figure as its just using a few tens of milliamps to charge my mp3 player/phone, then it shouldn't theoretically affect the cars battery but could it potentially affect the cars Passive Anti Theft system or any other monitoring circuits that modern cars seem to have these days? Well, it certainly never gave me any problems on my old fez? I've even left the interior light on in my old fez overnight a few times in the middle of winter and it has started fine first time the next morning(!) But then comparing my old fez to this new one is like comparing an old steam powered black and white telly to a modern 50" widescreen telly - more bells and whistles than you can shake a stick at(!)

Thanks to anyone with any ideas or experience.