In 38 months of ownership, I've never had an issue with the washer fluid the dealership puts in my car. And I use it a lot, +45" of rain in 8 months this season alone...

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'08 335xi (E90), 6MT, Arctic/Black, ZPP, ZSP (18"s), ZCW, CA, PDC, i-Pod
Ordered: March 7, 2008
Built: March 17, 2008
At port: March 19, 2008
Shipped on Graceful Leader: March 21, 2008
Arrived Port Hueneme: April 11, 2008
At dealer's: April 19, 2008
Delivered: April 21, 2008