How many amps dose a mini starter draw?

Any fuse is there to protect the wire not a device. So determine the guage of the wire, and fuse accordingly.

Also there are slow blow fuses and cir brakers, they can sustain a higher than rated load for a longer time than a standard fuse. This allows for inrush current of a motor.


THE REAL QUESTION...
why are you worried about the wire from the battery to the starter?
Not sure if even BMWs protect that wire.

The shorter it is and the heavier the guage, the more currant carring capacity it will have and not be over loaded.