How did the rear pads manage to wear into a little stripe?
A bit of an off-topic question, but have you ever seen an MDX with the CEL and VTM-4 lights on that wasn't caused by an EGR valve issue? It's stuck in a pretty rural area with no one to read the codes.
The whole pad was there. Most of it just wasn't contacting the rotor. Surface rust builds up a bit after it rains or whatever, the people dont drive it hard enough to wipe the surface rust off, more rust builds, and after years you get this.
Also, I cant see a pad FALLING OUT unless it was incorrectly installed. There is just no way.
It's possible that the adhesive was improperly applied and the friction material separated from the backing plate. In which case, it's the fault of the pad manufacturer and not Mitsubishi.