If it has factory fitted park assist then you will see the sensors on the rear bumper, 4 of them, they should also be colour coded to the bumper. You should have 6 in the front bumper also.
You can switch the park assist off and on from inside the cabin, to the right of the steering wheel next to the switch that you use to adjust the wing mirrors.
The wiring you are seeing may not be for the park assist system, these cars are all wires, they fart by wire.