I am nervous

[StartX5]

I used search function to search in forum. I typed these two words:
tranny then transmission and I got alot of threads that contain tranny
or transmission problems. Now I have learned that there problems/errors
with X5 transmission that users have posted here. It seems like X5 major
problems is transmission!? I know transmission is an expensive X5 part and labor to rebuild, to repair or replacement (up to $8K).
In addition, my cousin called me today from California that he has 2006 X5 3.0 and he got transmission problem yesterday and it happened on the way home from work. His X5 with 28K miles and this happened.

How do we drive X5 that keep tranny away from problems? Or it is just because BMW's transmission
is bad, poor quality?