I'm pretty sure they arrived on it, because I remember someone said "it brought the second wave of Autobots" in the film. But my point is, by "second wave" do they mean that the crew of the Xantium was those people and Skids, Mudflap, Arcee, Chromia, Elita-1, Sideswipe etc? Because if Dino, Que, Brains and the Wreckers have been around that long, might they not have been of some use in Revenge of the Fallen?