I wrestled with this myself, but couldn't get past the fact that I love the look of the M3 4 door but couldn't afford to sell my nicely modded 325i so I bought piece by piece the M3 body components. I bought my car last year for 14,5k a 97/98 M3 4 door cost 27-32k. I could put 10k worth of mods to bring my car up to M3 specs and then some.