From a outsider looking I think you will see this becoming more and more with OEM's owning dealerships.
You have to figure when dealerships are making little to no money on new truck sales the factory is in the same boat to a certain extent.
Crown here in the US is the perfect example and Raymond not far behind with the amount of factory owned dealerships.
Some cases it is the dealership owe's the factory so much money so the only way for them to recoup that is to take over the dealership. The other case I have heard of is the owners do not want to see what they have built brought to it's knees by the next owner and sell to the factory.