My factory ET lasted 9 years.
Originally Posted by BimmersGarage
For guarantee fitment (it just fits, no fighting with it to get it installed) and reliable functionality (coolant level sensor)
Yes, you've heard/read that the original ET do fail/crack/explode BUT that's usually after 5 years or 85+K miles whichever comes first.
All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident. - Arthur Schopenhauer