Whilst Marussia is saying it's due to contractual issues , Chilton is out saying that he's stepped aside so that they could sell his seat to generate funds to keep going .

That's two very different versions of the situation .

Hard to think of a contractual issue , but for a performance clause , which wouldn't likely be in place at a back marker team , I would think , that would result in problems at mid-season .
It's seems more likely that Max's version is correct .

So , we have an American in F1 .
Do we need ask who paid the ticket ?