Need help with xtrons head unit.

[Untamed]

Hiya I have a audi a3 2005 have also a xtrons 7" double din head unit. I'm been trying to get everything working on this head unit but I seem to be going around in circles. Once it's wired up I can't get the radio to work or pick up a signal without me touching parts of the wire at the back. I have no sound coming out my rear speakers since installing the head unit. My bluetooth seems to cut up randomly when I'm playing music via my phone.
I also brought a xtrons reversion cam to go with this but can not get the cam to work and all I get is white video feed.
All help welcome or point me in the right direction to being helped.