The internet is a big place. A very big place. If you happen to swing by the Australia's Office of Film and Literature Classification
website, therein lies the source to a rumoured Forza 3 (Ultimate Collection)
A classification request originating from Microsoft and Turn 10 Studios appears to reveal the fact that in the coming months we will see Forza 3
re-released as the aforementioned 'ultimate collection' which would likely mean the myriad of paid DLC packs, or at least a selection of them, would be bundled on the disc. At this time it's purely speculation however as the classification listing gives no additional details.