when I unlock the RR , for the first 20 seconds theres a ticking noise (more like galloping horses ) from behind the centre air vents - any ideas gents ?

Had the same thing some time ago... It turned out to be a parking ticked inside the heater motor... I removed the final stage resistor to have a look inside the heater motor.. I was able to remove the parking ticket from there..
Have a look here: http://www.fullfatrr.com/forum/topic14961-45.html 2002 L322 V8

The big black electrics box in the engine bay is ventilated into the cabin area behind the dash area.
What you can probably hear is the fan running that provides the airflow.
I think you can quieten it by stripping out the bits in the box and then lubricating the fan shaft.
Not worth the hassle imo, most cars seem to have this noise on un-locking.

Does the sound increase / decrease when you manually adjust the fan? 2002 L322 V8

No , its only when u unlock the car and wake it up . Lasts bout 20 secs then all quiet .

Had exactly the same thing recently. Turned out it was a broken blade on one of the fans in the heating / ventilation system under the dash.
I'll check tomorrow exactly what is was.

It was the motor for the footwell blend motor. It was turning further than the flap was able to, it could not be recalibrate do and was replaced.

Cost £30.53 for the motor and £110 to investigate it!

Sometimes my car also does some noises when I turn the key.

My mec told me it was the EGR self cleaning feature. It seems like a tchk tchk tchk
Could be?????

Besides that, there is also a constant tic, very light, tic tic tic going on.
that one is connected to the rev counter. the needle may be loose or with the teeth messed up, as most of the times the rev counter is crazy, It can mark 0 as it can mark 1500 on idle.