2017 XC90 Parking sensor service required

[Kingmunky]

I've got my XC in at the dealer's at the moment, having purchased the extended warranty after my selekt +1 year warranty expired.

I had the PAS warning for a while and it should have been looked at in January when my previous selekt warranty was still in use but the garage didn't fully resolve the issue so I had to re-book it in.

Now they've looked at it further, I've been advised the the wiring harness and sensors in the rear bumper are all ruined. Exposed to water and corroded due to, in the garage's opinion, "excessive off-road use". Notwithstanding that it's ridiculous to suggest a 44x4 is not suitable for off-road use, I've never had it off-road. I've been advised again that there was a lot of water pooling behind/inside(?) the rear bumper and that because it's there, they're sticking by the "you went of road and that's not covered by your warranty" line. So I'm on the hook for c.£1,200.

I highlighted to them that there are TSB's available that detail water ingress into the rear bumper and that is evidence of an inherent defect, but they flat out refuse to acknowledge this.

It just seems to me like this issue is well known if you read over various forums. It seems like an inherent defect, and don't even get me started on "it's your fault for taking a 4x4 off-road".. Rant over....

Any thoughts on the above, or similar experiences welcome.