Hardwired Power for Camera Car

[thisiswily]

Hey everyone, new to the Bimmer life (just purchased a meticulously maintained 2007 E70), and will be wanting to use this as a camera car for the film industry.

Goals will include wrapping the entire car in matte black vinyl, and chrome deleting anything shiny, as this will reduce glare and reflections while shooting a subject such as another car, or anything that can be reflective.

My main concern/question is about hardwiring power into the X5. Ideally, I would be running 4 monitors off power drawn from the vehicle. They are small, and do not draw a ton of power, and can always provide more information, if necessary. I'd love to be able to tap into the battery by using an inverter (unless anyone has any other ideas), and then running power to each seat under the floor, through the centre console, and up through the dashboard. Along with a power cable, I would also be adding a video feed cable for each seat, but that does not have anything to do with power.

Does anyone know where I can start looking for information on how I can best set up power so that the battery doesn't drain when the X5 isn't running? This won't be a primary mode of transportation, so it may sit for days or weeks at a time, and I'd hate for the battery to drain before a big shoot.

Any tips/help would be greatly appreciated, and I look forward to chatting more with all of you!

I've attached a "before" photo, and will definitely post another one after any alterations have been made.