It was working fine and suddenly stopped beeping. I checked the sensors installed in the bumper - they both have a rapid clicking sound when I put my hand up to it.

Can anyone help me with this issue or let me know where the speaker/beeper is located? Thank you!

 

Hello there I have asked a very similar question and the answer i got was that iit is located in the driver's side of the boot .
here are the instructions I was given.

Drop the third row of seats and remove the wheel change tray. Move the carpet as far forward as possible.
Remove the small storagel compartment lid.
Undo the 10mm bolt at bottom left of panel. ( The bolt has a clip on cover and tie handle attached ).
Unclip trim over lock and across boot ( 2 X clips )
Pull panel and unclip as much as you can and you will see bleeper in top section behind the panel.