Managed to fit my head unit and get it working well almost lol, one thing it won't play DVDs as it thinks I'm moving even at standstill? How do I remedy this? What/where do I connect the cable to or how do I bypass it? Thanks again.

 

You need to earth it on something other than the handbrake. The headunit in my wife's a3 I earthed to the cage I think.

 

Thank you all now working as it should be.