1989 BMW 325i clutch

You've probably blown out the slave cylinder which is on the drivers side of the transmission near the bell housing. Those cars like to leak oil from the oil pan which coats the slave cylinder and softens the seals which then blow out. The part is cheap and the fluid is just DOT3 brake fluid. Your brake master cylinder is on the firewall inside the car and the two cylinders share the same reservoir. Also check the rubber oring gasket on the bottom of the reservoir for leaks by looking for wet peeling paint below the reservoir. This is also a cheap easy part to replace