Gloves off today guys, crackling speakers sent me to amp in n/s rear. Wet and wild. Ripped the lot out and barrowed it all to the barn to dry out. Checked the remote unlock cassette rx and this too is u/s! Where is all the water coming from?

Tailgate seal, rear space vents or bungs. etc.

Have a search for

water ingress

lots on that  Cheers
Richard

(there are no such things as an ordinary FullFat, an ordinary cat or too many tools)
2011 TDV8 Vogue Santorini Black
Gap IIDBT

My 53 plate had water ingress and i traced it back to the rear Quater side screen, stripped out the trim on the left hand side to get good access to the window, hose pipe on the outside and after a short while water was creeping in, i used some windscreen sealer along the bottom edge and up the front edge (applied on the inside) !
this has cured my water ingress.
tailgate rubber is very common fault, i changed this prior to the above.

Thanks looks like a job for a dry day!