There are two types of iDrive which came in 'our' cars, CCC and CIC. CCC is up to 2008, CIC is 2009+. There is NBT/EVO but that is for newer vehicles, and its not something that I looked into much. It could be argued, that if you went from no iDrive to any sort of iDrive, NBT/EVO may be where its at, but I just don't know whats involved and there are a lot of electrical changes that went into the car around 2009. When people talk about CCC or CIC, they are also referring to the radio itself and not just the display.
I had a 2007 E90, with CCC iDrive. Flipped that car and later bought a 2009 E93, also with iDrive but this time CIC. The differences are many small things under the hood, but the CCC iDrive is nothing to write home about. The CIC isn't either, but it does look better and has a built in hard drive.
There is a built in factory backup camera software which can be enabled, but it was never an option for the E9X, but instead a vestigial carry over from some E60 cars. You can use a box which emulates some of the exensive OEM hardware found in the E60's with this option and you can get some built in backup camera menus to work properly. I don't use this built in menu however, I always use the aftermarket one with the AVIN or the xcarlink since it uses the full screen size instead of just a small portion of the window. OEM screen sections off half of it for the parking sensors, but aftermarket systems just overlay the backup heat maps onto the image itself.
To keep a complex topic short, I wouldn't put CCC into your car, its not THAT important. If you did put something into your car, make it at least CIC, and even then if your goal is backup camera, then you can accomplish that in other ways. I think that AVIN also sells a built in screen now, you have to cut your dash up but honestly its probably a better route than the wiring mess you'll endure to follow the OEM footprint. And even then, you'll honestly have some weird wiring going on most likely since you won't have factory harnesses. I don't know what is involved in doing a CCC to CIC upgrade, I know people do it, but you run into wiring weirdness when you start changing a lot of stuff, ask me how I know.
