Could anyone help, I have been trying to replace the Parking sensor Module on my 2017 w205 coupe but can't seem to find it, I have looked under the passenger footwell carpet, I have completely stripped the boot out, checked under the rear seats but to no avial,

Any help would be appreciated 👍

If you goggle the part #, you usually find a diagram with the location. Is it this one? If so, then it's on the left side of the trunk according to this diagram. Number 170 in the diagram. However, I know I looked it up for the C63 as that's what's in my profile. The C250 wasn't sold here, but I'm guessing the standard modules are in the same place. FWIW, Google AI says its on the passenger side in the transmission tunnel accessible by lifting the carpet. That's passenger side in case of LHD, so in your case it would be driver side with RHD, so not sure which is correct, but finding the diagram for the correct car and part is your best bet.

Yes I found that diagram and that's why I stripped the boot out, Somebody else said under passenger footwell, but not there either, I am thinking it's under the passenger seat but just wanted confirmation before steipping the seat out

Just remember, since you are in the UK, passenger side would be your driver’s side. They don’t move modules left to right between LHD and RHD unless they have to to make room for the pedal box and steering column and because the dash is mirrored, but the rest of the car doesn’t change.

For a W205 coupe it's behind the left side trim panel in the boot. Not under the floor. Remove the carpeted side panel near the rear light access flap. Module is a small silver box. If not there check behind the glovebox some late 2017s moved it there.