I just replaced my heater core in February and again in June now in august I am smelling antifreeze again. No fluid in the floorboards yet so I hope it's just my mind playing tricks on me. Although I am the fastest heater core changer outer in the midwest by now. I am fairly mechanically inclined to so it's not like I have been putting it incorrectly and the last one the leak was in the middle with no bent fins

 

I'm about to undertake the FOURTH replacement in my 03 S. The situation is beyond absurd. Can anyone shed some light on why these things keep failing?
FWIW, I replaced a long-since failed radiator fan a month or two ago...