Originally Posted by rzm3
Since you already have ZCP, the only thing I would do is to get a high-end coil over... at least KW CS or equivalent. Don't bother with the lower end set ups. The M3's suspension, while somewhat soft, is very competent and predictable, and you haven't experienced its true potential until you've taken it onto the track.
Good quality coil over - do you mean replace the stock shock or retain EDC/stock shock and get a sleeve-over system?