Going to fit a rear view camera that also has the option of including side and front cameras.

Before i order would be grateful if anyone has any manual extracts or advice to assist with the following?

1. Side camera:-

To fit the instructions advise drilling holes in the underside of door wing mirrors (18mm) and feeding cable through wing mirror inside door and through hinge rubber to car.

Question. Can i remove just the wing mirror blanking plastic trim from inside the car with out removing the whole door trim and feed a cable from the underside of the mirror into door from this panel and then pull out the rubber hinge gromit to feed in to car?

Does anyone have any manual pictures for wing mirror door assembly removal?

2. Front camera

Does anyone know where i can feed a camera cable from inside the engine bay to inside the cabin?

3. Also looking at fitting rear headrest screens for the kids in the back

Questions has anyone done this and how do you undo the seat backs to get the cables out of the bottom of the seats?

Here's a link for seat assembly (72) and seat covers (74)

http://elsaweb.spaghetticoder.org/nav/EN/Skoda/Superb/3T/4/2944/18924/72/

Just watch out for the airbag mechanism while you're there.