How much did you put in? If you likely overfilled by just a little bit, then it may not be that big a deal. But if it's any significant overfill, then you definitely need to drain some out because overfills are not good. The best way to cure overfill on this car, from what I've heard on this forum, is to drain the front sump. There are two sumps on this car and therefore 2 drain plugs. Let the front one drain and that should be about a quart. If you need to top off slightly afterward then you can but I imagine that won't be necessary (level will probably be somewhere in the "OK" range after enough driving to get a proper reading).
Originally Posted by sensi09
You can pump it out from the top. Try a mityvac pump from sears or somewhere else local.
I remember seeing on this forum somewhere that sucking out from top is not possible on the M3. Don't recall exactly why...
2015 ///M3 | BSM/Full Black/CF | DCT | Silver 19s | Executive | Lighting | DAP | Adaptive Suspension | HK | Enhanced USB | Tint
Past BMWs: 2014 550i, 2013 M3 ZCP, 2012 535i, 2011 E90 335i, 2009 E90 M3, 2008 X5, 2006 330i, 2004 330i