Welcome, here are some useful links, hold out your hands:
1) Here is a link where you can find your owner’s manual (in case you lost it) and videos about your car
http://www.bmwusa.com/Standard/Content/Owner/dgh.aspx
2) Here is a list of useful DIYs (Even if you don’t DIY at least you know what they do when they work on your car)
http://www.e90post.com/forums/showthread.php?t=1721
3) This link is a must read if you are thinking about modding your car,
http://www.e90post.com/forums/showthread.php?t=66970
4) If you are thinking about extended warranties take a look here, especially at post #20
http://www.e90post.com/forums/showth...ded+warranties
5) If you have an iphone (android app coming soon), download the bimmerpost app
http://www.bimmerpost.com/tag/bimmerpost-app/
Again Welcome and Happy Motoring!
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If no codes are being thrown use Chevron Techron fuel injector cleaner (concentrate). It solves rpm fluctuating upon cold start-up. Also, for most BMW problems start off by scanning your car with the Peake Research Tool. It contains the actual BMW codes. If you want to register a newly installed battery for free (just buy a $10 cable) and google/download BMWLogger