OEM. From talking to BMW parts guys, springs obviously differ between, say, competition pkg or std suspension. They can also change based on the options you choose, i.e. premium stereo.
2011 E92 M3 DCT
1991 Spec Miata
2008 E92 M3 DCT - KW Competition 2-way / Brembo 365 BBK / OMP ARS racing seats / rear seats delete / GT4 aero / AiM EVO4 data logger / SmartyCam racing camera
2008 E92 M3 6MT
2008 E92 335xi