probably between 3500-3600 pounds depending on how much gas is in the tank.
there are some M3/M4s in the 34xx range but you need a manual trans.
here is some data for you:
https://f80.bimmerpost.com/forums/sh....php?t=1029340
https://f80.bimmerpost.com/forums/sh....php?t=1003735
https://f80.bimmerpost.com/forums/sh....php?t=1077612