BMW Repair: 99 323i lost all power while driving, bmw 323i, shock mounts

Question
My daughter drives a 1999 bmw 323i, we have had no problems
with the car.  It does make a strange clunk noise that comes
from the trunk area when she lets out the clutch.  Today she
was pulling into the grocery store and everything shut off.
Just turned off, dead as nails...I do not know where to
begin, Do you have any ideas what this may be, both issues
the clunk and the loss of all power.

Answer
Checking all the wiring that goes in that area.The clunking sound probably rear shock mounts.Which means new shocks and mounts for the rear.Close inspection is what needs to be done you could have cut a wire.There are many place to go from here,checking power is the first,grounds next.