We install the majority of our cameras using a fuse holder adapter, this allows us to fit the camera without cutting any cables.
If it is not possible to wire them from the fuse board then the installer will look for a suitable alternative power source from which to take the permanent live feed. In most cases this will not invalidate a guarentee or warranty on the vehicle but it is the customers responsibility to check this prior to the installation date.
Our fitter will locate your car camera as discreetly as possible whilst still allowing for the best viewing angle. This would usually involve positioning the camera neatly behind your rear view mirror.