It's interesting to see how things that don't seem like they're related to combat (or whatever your sufferer's trauma may be) in actuality DO have everything to do with it.
For example, my vet is an asshole when it comes to his vehicles. He's overly picky, almost to the point of obsession over them. He has sold a brand new vehicle because he heard a "squeak" that nobody else could hear. He rarely lets one get more than a few years old before he trades it in and gets a new one. He constantly maintains, improves, and tinkers with them. Meanwhile, he has torn into me for the state of my car. I am not a car person... I tend to forget to get oil changes on time, and run low on gas. It's also lived in family car and a few years old. I like my car, it's paid off and runs great. He is constantly on me about getting a new one. We have had many an argument and rage over some kind of vehicle issue. I tend to tiptoe around it, and assumed it was a personality quirk ramped up by PTSD.
It took me awhile to realize it was related to his Trauma. He was Cav, and in the Cav you take care of your mount. He has injuries from not one, but a series of roadside IEDs. The state of your vehicle can make the difference between life and death. PMCS, then more PMCS.