Theoretically, even if you have to hose it down once in a while, then it's not really maintenance free is it? That being said, one of the not so "maintenance free" issues I've discovered is heat damaged vinyl siding. Sometimes it's as simple as seeing the gas or charcoal grill positioned next to the house and immediately knowing what caused the damage. As my frequency of contact with vinyl siding increases, the incidence of various forms of damage increases.
In one particular instance, the houses were spaced close together, about eight to ten feet apart, with large bushy vegetation at the front and rear of this outdoor hallway. Also, there were windows on the opposing walls (I've still not been able to figure out what you were supposed to be looking at). Well, the siding on the home I was inspecting was fine, but the siding on the neighboring unit looked like a surreal painting or a Martian landscape. Large areas of the siding had started to melt or shrink. There was no evidence of a fire, and then it struck me - the track of the sun shined down along the length of the unit I was inspecting and reflected off the windows onto the neighboring house exterior. Also, the bushes at the front and rear stopped all airflow, thereby creating a huge solar oven, but only on the one side. Amazing!
I was told by a great mentor-inspector once "Over time you build a picture of a 'normal' house in your head. When doing an inspection, you start to look for the things that don't fit in the picture." I have since learned that you sometimes really need to think outside the "normal" box when trying to figure out the more unusual conditions you encounter.