That sure seems like a design flaw. It can't be a surprise to an engineer that this area will get very hot, and therefore all components (including the wire insulation) should be spec'd accordingly.

 

im sure it was spec'd correctly. You know, to last the warranty period not the life of the car. Also i sincerely believe that parts have engineered design failure point. Not just automotive but everything. Replacement parts are a huge income source and market. What do you sell if theyre build to last forever.