Ahh great ..thx for pics too.
My front plastic trim sections are very like that and the locking bits but much smaller.(no sensors on the front either).
The above is the extent of my knowledge^
The only other possibilities I can think of are that.
1. Its not the sensor at all but the actual control unit or
2.Perhaps the fault has to be reset
ie maybe the far left sensor from the drivers seat is gone or the one beside it but:
The fault still has to be reset for the unit(s) to work.
2 ways to reset a fault yourself
(a) disconnect the battery and reconnect it works for some fault codes ive read, once the problem is fixed.
(b) buy one of those code reader fault resetting devices off
Thats all I can suggest..
!if you are thinking of disconnecting the battery! make sure you have the reset code for your radio.
The rear sensors.. do you think the fault was misread and it should have been nsr?