If you haven't already, pull the fuel pump fuse. It can't run with no fuel. Sounds like an ugly electrical problem. The trouble with these problems is they can be something simple or horrible. You won't know until you start. I would start at the place where the smoke came out and check for burnt wires, bundles, etc. Then check all the fuses and relays.
1995 325I, window tint, K&N, debaffled airbox, BMW #104 wheels, Nighthawk low beams, smoked side markers, smoked corners, smoked taillights, M3 stlye heated mirrors, various interior bits, Bosal cat-back.