Originally Posted by Kirk S
I've got to ask why! To stop leaks that may occur before break-in or to hide bad plumbing?
We can only guess, it's probably to address small leaks and avoid dealer/warranty repairs over poor build/part/seal quality. Bar's Leaks HDC tablets claim to be what a number of vehicle manufacturers use and that it's for more than just stopping/preventing leaks.
What I do know is that these are the same tablets that are relabeled as Mopar stop leak pellets and this caused quite a stir among Jeep JK owners a couple of years ago because the coolant overflow tanks would end up with sediment in the bottom from them and people were freaking out. This was around the same time that the oil coolers on the 3.6 were having problems and some people were ending up with clogged heater cores.
Anyway, I'm sure the manufacturers that use them see them as a cheap way to try and avoid "unnecessary" warranty repair costs.