Rx450H Exhaust - Achilles Heel?

[motowpk]

Regarding when and where the damage happened, we know when and where the damage happened with essentially absolute certainty. As described in a previous post, at the stop light at the end of the exit ramp from the interstate the driver of the car stopped next to our RX450h caught the attention of the front seat passenger in our car and told them they saw liquid leaking under our car. I know from inspecting the expansion tank level subsequently that the amount of coolant that does leak is quite limited, either due to the heat exchanger coolant valve being closed, how the coolant supply is connected to the system or some combination of the two, so that the damage must have happened within a very short time of it first being observed at the end of the exit ramp since the amount of liquid that was lost was small enough that it would have been exhausted within a few minutes at most. This places the damage having occur on the interstate - not offroad.

As far as it not being heard, there is certainly some ambient noise traveling at 65 mph on an interstate with vehicles in adjacent lanes, but given that the RX450h is a quiet vehicle the noise of the impact must still have been limited for neither the driver or the passenger to have noticed it. I have also noted that the magnitude of the impact was such that while there were abrasion marks on the body of the heat exchanger, it was not deformed at all, indicating the coolant tube and actuator are not as robust as the heat exchanger (and by extension the catalytic convertor or muffler whose bodies appear of similar weight as the heat exchanger).

As far as the protection or exposure of the heat exchanger actuator, the photos speak for themselves.

As mentioned before, beyond the question of what protection Lexus should have provided for this component there is the issue of making a replacement heat exchanger available only as an assembly running from the catalytic converter through the muffler. And, as again previously mentioned, this same assembly and replacement cost would be incurred if you needed to replace the muffler or catalytic converter on your RX450h. That in conjunction with Lexus' pricing level of this assembly makes this an excessively expensive risk to something that lives under the car. Yes, I know it is an expensive car and one should anticipate maintenance and repairs to be relatively expensive, the replacement for the RX450h is in the same category in this regard (a BMW). Even with an expensive car there is consideration of value and for a muffler replacement, as an example, to cost $5300 is not reasonable value.

And finally, also as previously mentioned, my posting this experience is not to vent, I'm done with the vehicle, but to alert other owners of this potential risk.