@firemnsim - I have not looked at the diy option but may look at that..
@chriag - Japex.. will look into as Watford is down the road and I am off all week. Need to get a price for the fluid change.
@zmanalex - the clunking is when the car is idling. Does it from drive to reverse and vicer versa.. sounds like the clunk is from the between the gearbox and rear wheels. No matter if hot or cold it does it. I have never checked the level to be honest, would not even know how to...
They may be fluid for life but I had a bmw with a sealed for life auto box and it was recommended to change the oil, esp as no oil last forever and will offer less protection as it gets older. I do not plan on selling my car, it will go when i do.. lol. So thought the fluid change would help longevity esp as my car is an import and I reckon over time the auto box will become difficult to source down the line.