Has anyone installed a car Backup camera?

[tomreys]

I have installed reversing sensors in past, where you take the power from the rear light-fairly easy.
Need to order a reversing camera for the new car, and I'm a bit confused as to how you get power for them.
I still see you connect to the reversing light powercable at back of the car, but how do you power the monitor itself?

I see there are some kits sold where you have to plug it in the 12v socket of your car the monitor, which kinda sucks...

I'm looking now at either of these 2 kits:
There are no real instructions form them, but still show that you must connect to some power supply, just wondering if it's meant that you need to connect to the car battery directly or you can just connect to the reversing light cable like for installing the simple reversing sensors?

https://www.ebay.co.uk/itm//312623779616
or
https://www.ebay.co.uk/itm/352648000480

Perhaps maybe someone has ordered exactly  these in past? How were they?
I see those are like the 2 most popular dirt cheap versions on the fleabay.

[123Drive!]

I am using Garmin BC30 which links up with my Garmin SatNav.