1995 BMW 325i Base Sedan 4-Door 2.5L

This is a either a fixer upper or a parts car. My Son bought this car from someone who claim it ran and all it needs was clutch slave. Car has not ran right since it was bought home. I put NEW clutch master cylinder and clutch slave on it 3 ignition coils cam position sensor spark plugs fog lights and left taillight lens. car will start but backfire through throttle body. Not sure what is wrong but tire of buying parts. Ill let someone with BMW background deal with that. Window in front needs parts or adjustment to go up even. back windows work fine. door panels on front torn off not in god shape. Not sure of exact miles because its just give all 9s across gauge. This is AS IS car. I have title but never could get back with owner to have notarized and send off. So I can give a bill of sale for it. Can have title also.