BMW has a very strict Motorplan Policy, all new and Approved Used vehicles must be prepped prior to sale to be in accordance with this policy.
This is usually in the form of a 4 in 1 Auto Armour Package that costs the Dealer R600 and is basically a glaze, wax, tyre shine and the interior is scotch-guarded.
It has to be done, in fact Motorplan actually also requires the car be washed at every service, hence you getting a clean car back.
Of course, whilst this is a nice thing, it only lasts for 2-3 months so I would recommend getting the prepped through a professional outfit. :=):