Shade Tree Mechanic...Round 2

Recently I had a surprise as my headrest popped open while I was backing down my driveway. I didn't know that my headrest had this safety feature built into it. It is there so that during a collision the headrest expands and works to prevent / minimize whiplash during an accident. The only issue is I wasn't in a collision. The head rest just popped open while I was traveling at low speed, so there was no real impact to me beside being startled.

Looking inside the headrest, it looks like it was a creep failure on the plastic part. The plastic frame is spring loaded and a metal pin is held inside a solenoid. In an accident the pin should be released by the solenoid and allow the headrest to expand. Inside my headrest the plastic frame failed over time and the headrest deployed without the solenoid activating.

It was an easy fix to swap out the headrest, and it looks like there is a design change to new headrests, but this goes to show the importance of design of a component and thinking about different failure modes in a product lifecycle.