Just tried changing my headunit to get rid of my dropping signal (process of elimination) it needs a security code and I don't have it. Is there any way to get the code for free? I begrudge paying £13 to unlock it when it might not even fix my problem. And if I need to put my original back in, I'll need a code for that too. This car will be the death of me. It has sucked from the day I got it. 

Hello Miley,

Possibly pessimistic, but free radio codes maybe a thing of the past, and has regrettably moved on to where £13 has become loose change in terms of ‘parts’ for cars. Appreciate we all want to save money, but more often than not, it’s turns out to be far more convenient and time saving just to bite the bullet and pay. 
Having said that, it could be worth waiting a couple of days or so Incase someone does come up with a free source. 
Kind regards,

Gareth.

if i read this right you have no user manuals for this car. Then you bought another radio unit without it's code? pay the £13 then another £13 for the original radio code. The four digit number looks remarkably like a code. Worth a try.