Land raiders. Fellblades. Rhinos. Typhon siege tanks. Most of them have machine spirits. Some, like a land raider's, are practically sentient. Some, like a super-heavies, probably are sentient. Some of them even already have fluff that tells us about them - like the story behind typhon siege tanks, which states that their machine spirits are surly, resentful, and hard to control. Others, like the rhino's, are barely there and barely mentioned in the backstory.
Nevertheless, based on the vehicle's background, purpose, and reputation, what do you think their machine spirits are like?