I haven't seen this in the U.S. on Elantras, but I have seen it on Sonatas.
It appears that Hyundai puts a rubber sleeve over the parts of the pipe
that could rub things, and on the Sonatas, it sits in a low spot and tends
to collect water and the line rusts. The reason that they wouldn't have
seen it during the routine maintenance is that it's covered by the rubber,
so they won't even know it's rusty unless there is fluid coming out of the
rubber. At least, that'll be the case if it's similar to the Sonata
issue.

To Hyundai's credit, the replacement lines on the Sonatas have a sleeve of
different design that prevents water from entering, so I wouldn't expect
you'd have to continue the process on your car. I don't view this as a
product quality issue so much as a design flaw which was later corrected.


As for the Santa Fe, I think the 2.7V6 is very reliable. The 2.4 seems to
have significantly more problems, and the 3.5 is too new to draw many
conclusions, but based on the problem frequency with the XG, I'd expect
the 3.5 to be less reliable than the 2.7.