I realized that I don't even know the build date of my car. I checked my original factory sticker (the one they stick on the window at the dealer) and that didn't have any info, and there's no info in the manual.

Any ideas where we can look this up?

 

On the tag inside your drivers door jamb, should list month and year.

 

go here: http://www.realoem.com/bmw/select.do
and enter your vin#

 

This. Can't miss it.

 

http://www.bmw-z1.com/VIN/VINdecode-e.cgi

 

Here's an example: 2011 535iA, build date November, 2010. Found on driver door jamb.