what do you mean by "add pins"?

the car has got a tv tuner. so i wont need that cable then?

i will make a av lead by following these instructions,

You then need to get two phono plugs from your local electrical retailer, to which you solder the four leads above.

Once you have done that you simply plug in the four cables to the white socket...

Pin 6 : AV Video + (The centre pin of one phono)
Pin 15: AV Video Gnd (The outer ring of the same phono above)

Pin 4: AV Audio + (Centre pin of second phono plug)
Pin 5: AV Audio Gnd (Out pin of second phono plug)

If i wire it up like in the diagram then i cant wire up the dvd player because the reverse camera will use the AV conection instead.