TIP!
I followed the advice on here and had my new car professionally detailed.
The biggest problem is that the cars are transported to the docks on an open railway carriage and minute particles of metal from the railway system land on all the exterior surfaces of the vehicle.
My detailer told me my car was covered in these metal particles all over, one of the worst he had seen!
When the car is cleaned at the dealers they just pressure wash it with some form of degreaser (I watched it done but couldn't get the exact info from the guy operating the pressure washer), then it is shampoo washed and 'polished' and thats it!!
However the degreasing and shampooing doesn't remove all the metal perticals so you can guess for yourself what happens when the car cleaner rubs (swirls) the shampoo all over the perfectly clean factory finished surface.

Hopefully some pics will be posted of my Pro. detailed car standing alongside the dealer prepared cars.
You can decide for yourself if its worth the money when you see them, but from my experience I will never buy another new car without having it fully detailed by an independent Professional.
Hope this helps.