It means that a X-class vehicle may be incoming.
This
cat which raced back when BMW and Toyota got bored of Le Mans and decided to try their hand at F1 came to the mind of more than a few people over at the fm.net forums. It's a bit of an outlandish guess that's been given the slightest hint of credibility only by the X class lobbies going
kaput, tho.
Ah, whatevs. We'll find out soon enough. It always feels like Christmas when a Forza DLC is coming... You know the general shape of the wrapped gifts sitting under the tree, and that makes the wait for the moment of unwrapping 'em almost unbearale!