Whatever happened to the concept of DLC and Micro transactions being nice additions rather then requirements. From everything I've heard of Forza 5 so far, it's straddling the line between 'required' and 'nice addition' very awkwardly, which is probably the most dangerous kind.
Mass Effect 2 and City of Heroes are the first games that spring to mind that did 'nice addition' well, with the extra missions in ME2 not required but filling in a lot of details between ME2 and ME3 while City of Heroes had plenty of content and character options even before paying extra.
Forgot who mentioned it, but I agree Forza would benefit from paid for content in previous games being transferred to the next game, either for free or for a small price. Forcing you to buy the same content for each new release is insulting.