As I was coming home from the gym on Wednesday, two kilometres from my house, the Protege's engine gave a loud pop, followed by uneven operation and zero engine power.
The problem ended up being that one of the spark plugs had wiggled loose and eventually was blown out of the socket by engine pressure. This resulted in no pressure in the engine block, meaning no power.
While fixing it took all of two minutes (thanks to the handy toolkit in the trunk), it is what was going on in my head that was surprising. My first thought after instinctively shutting the engine off was "time for that new BMW?" I would have expected something more along the lines of a more logical "I wonder what rattled loose?" The mind is a strange thing.
So, no, it is not time to get a Bimmer.