Lights, dash, clock etc going mad!

Hello guys
I have a friend who h as brought a 2005 Diesel {BMW Engine} Range Rover Autobiography cheap!
I did warn him but he would not listen!
He has had it 2 weeks and now its got a life of its own!
Rear lights flicker along with all the dash lights and once you turn them on, they will not turn off! even when you take out the key and lock the car!
Clock will decide to have a trip on speed and spin round at top speed then it will stop and randomly go off on one without doing anything.
Indicators will flash extremely slow { 3 times a minute} hazards wont work at all.
Wipers work sometimes and not without touching anything they will start .
checked all fuses, checked connections from Battery
By the way, we haven't had any rain but the day after the rain, problems started.

Sounds like water has got to wiring somewhere also has it had any led bulbs put in as they tend to cause havoc wit the lighting module , other with more experience then me will know more.

Water ingress somewhere would be my guess.