Reversing camera on '04 E53/X5

[UKenGB]

Once again I search and search but cannot find all the answers I need, so have to resort to asking for yet more help.

I want to install a reversing camera. This is specifically to enable me to see the trailer hitch as I reverse up to it, a process which otherwise takes a lot of getting in and out pf the car and nudging it slightly to get it close enough. And before anyone asks, yes the trailer is big and IMPOSSIBLE to move to the car. So.

I have Nav and TV Tuner so there ought to be a video input available, but I cannot get to the bottom of precisely what is required. Hence my questions.

- As a UK car, does it run PAL video?
- If so I would need a PAL camera, yes?

- Why would I need e.g. a VSM (from EAS)
Is that purely to allow an additional video input to be used? Or is there some other more empirical reason for its requirment?
Would I be able to hook up iPod video with a reversing camera installed but no VSM?

- How does it all integrate with the reversing switch?
Is a relay required, or does the OEM Tuner handle this itself?

- Is there a list of exactly what parts are required?
- A wiring diagram of how it all connects?

I don't have a problem with the general principles of what's involved here, but I need to know the specifics of how a camera is integrated into the X5's wiring to give me some idea of which camera I should consider, Bumblebee from EAS, BMW's OEM unit or another alltogether.

Thanks.