Thanks for that info will give Your suggestion a whirl. A couple of weeks yet but Ill let you know who it went.Hi and welcome
You would be better to fit a DIY aftermarket rear parking sensor kit off Ebay, It is easy to do and far cheaper than buying Ford parts and trying to retrofit. I have fitted a kit on my Wifes previous car, and it was easy to do. Just took four hours to do the job.
Here is an example off Ebay below, and what you want is a minimum of 4 sensors that covers the whole rear area, do not go for less sensors kit as these are inaccurate. You also need with the kit the hole cutter included to fit on your drilling machine which is the right size to cut the hole for the sensors. Also on some kits you can ask the Ebay seller the colour of sensors you need for the back bumper. I emailed the Ebay seller which colour I needed for my Wife's cars bumper.
The 12V supply is taken from the reversing light, and hence powers up the system when selecting reverse. The black box which connects all wiring is fitted somewhere out of sight in the boot. The sensors just plug into it. You get a visual/audio displays to monitor how close you are getting to an object.
Here is a typical Ebay kit with black coloured sensors...Have a look at Ebay for all the different kits and prices.