Hi - I have a Focus as a hire car and was going to return it today when I noticed the rear parking sensor was going off for no reason when reversing off the drive. 

I had a look and this is what I can see, photo attached.

Presumably someone has hit the car while parked,  is this a piece of trim?  There's no obvious damage other than this missing piece of plastic.

Any idea cost to replace?

Thanks for any advice, I have extended the hire so I can hopefully rectify this rather than get charged a fortune by the hire company.

Is this it?  Is the sensor going off because it's missing or is it damaged?

https://www.ebay.co.uk/itm/167225894655?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D280553%26meid%3Dd09d563f5d4f4148aedeee9ffe9e3c8e%26pid%3D101506%26rk%3D1%26rkt%3D10%26sd%3D167242568667%26itm%3D167225894655%26pmt%3D0%26noa%3D1%26pg%3D4481478%26algv%3DDefaultOrganicWebWithV11WebTrimmedV3VisualRankerWithKnnV3AndUltBRecall%26brand%3DFord&_trksid=p4481478.c101506.m1851

That is the rear towing eye hole, not a parking sensor.

You can see one sensor in the painted panel above and to the left of that hole.  

The warning may be going off because of the dirt on it.  Give all 4 a wipe over.

9 minutes ago, davidjw said:

I noticed the rear parking sensor was going off for no reason

The reason is the back bumper is scruffy and the sensors are obscured. Wash the bumper 👍

Thanks, what an idiot!  Cleaned it up and the parking sensor is now fixed 😀

It was fine this morning reversing off the drive, just assumed someone hit me as I don't remember the towing eye being exposed when I picked the car up but I suppose it might of been.

Cheers, relieved!

👍