Hey all, new kid here. I've had my 2006 RX400h with 206,xxx miles for a bit over 2 years and have had generally trouble-free service. Until I didn't!

About 3 months ago I started seeing some coolant under the front valence on the passenger (USA) side. I had 2 different places diagnose and they both said the same: radiator and auxiliary water pump need replaced. (Did not go with OE parts) So, after that service was completed, I was happy to be driving a leak-free car again. About 6 weeks passed and noticed a small spot under the same area. Took it back to my guy and he said the pressure test revealed a small leak from the radiator and just chalked it up to receiving a 'bad' radiator and he replaced it. All was good....until

FF about 1 week ago, I noticed a slight 'sweet' coolant smell (yeah, IYKYK!) pulled into a parking space and sure enough there was a trail of coolant under the car and steam rising from under the hood. ARGH!!!!!

Got the call from my guy a little while ago to hear him say that it's exactly the same leak at the same place on THAT radiator!! Says he doesn't believe it would be ANOTHER bad radiator and that it seems that it's "...building up too much pressure..causing the tank to rupture". Anyone here have any ideas what could be happening to cause the radiator to start leaking at the seam between plastic and alum radiator???

Thank you in advance for your thoughts on my dilemma. Very appreciated.

Notafan