Originally Posted by M-bitious
My car has both EDS and M-drive and is fully functional with OEM behaviour. Hartge have developed them specifically for the M3. Had the Hartge springs on my M6 and had no problems at all.
That's good to hear. What makes you say the functionality is consistent with OEM behaviour though? Have you driven your car in non-modified and modified versions hard on the backroads or a track? I don't mean to challenge you on this. I'm just trying to understand where you are coming from as this is a mod I am considering. Also, do you have vendor data on the stiffness of the new springs, and how that compares to the stiffness of the stock springs?