Estima Hybrid 2008 multimedia steering wheel controls +++

I have just bought a 2008 Estima Hybrid, there is no multi-media controls on the steering wheel and there is an aftermarket double din stereo unit in place. Nothing is connected to the DVD screen or the reversing camera either.

I'm looking to add steering wheel multimedia controls, enable the DVD screen to be used and if possible reversing cam too - sat nav on the screen would be useful but is not a massive issue if not. 

Any advice please?

Topic moved to the Estima forum.

for the dvd screen to work you will need the remote for the unit if it is OEM.  signal out depends on the head unit.  there should be a reverse camera already so perhaps check the wiring.  if you are interested in some steering wheel buttons let me know i have the attached for sale.