***PLEASE READ, FOUND SOMETHING***
I've actually had 2 go on me leak..and everytime it's mainly after my car sat through storage in my garage for winter..now i'm going on my third. I've had them all under warranty so it wasn't to bad..but i've finally figured out my problem i was having(lol knock on wood)..had nothing to do with "chassis flexing" like most were going on about at correl. It's called coolant electrolysis..aka a stay electric current getting carried through the coolant.
I measured my coolant and found over 50mV with the car completely off. I replaced the coolant and in a matter of days it was back at over 50mV..I noticed when i turned on my radio it would shoot up in mV's. I refitted the ground behind the dash to a better location, replaced the coolant again and tested in a few days..everything was perfect.
So if you have a bad/corroded/faulty ground wire/cable..it's very easy to get coolant electrolysis which can finish a aluminum rad in a matter of days!!
Anyways I'm not stating this is the problem for all these leaking radiators, but in my case it was..Here's a link to what I used to diagnose my fault i had..check out some of the testing they did, goes to show why some ppl had no problem with there stock rad but started having radiator leaks when switching to a large aluminum rad..
http://www.tectaloy.com/images/documents/Tectaloy%20Green%20Book%20Vol%202.pdf