Might have answered my own question....
Could be this
Long Term Update 3: 2009 BMW M3
2009 BMW M3 Front Three Quarters Driver
Long Term Update 3: 2009 BMW M3
December 14, 2009
/ By Ron Kiino/ / Photography by Jessica Germiller
"I developed a love/hate relationship with the M3 after tooling around Southern California," notes senior editor Edward Loh. "I do love the shocking acceleration; this thing embarrasses many true sports cars not just from a light, but from 60 mph on the freeway. Hit the M button, mash it, and you're gone -- just remember to pull back on the right paddle or you'll bang into the limiter in about 1.5 seconds."
And the hate part? "Over speed bumps, in and out of driveways, any motion that puts torsional stress on the chassis induces a creaking noise from the back seat.
http://www.m3post.com/forums/showthr...ighlight=creak