so i was forced to leave my bmw in a parking lot with cold conditions (-10 to 30) for 4 weeks while on vacation. When i started it up today the clutch is horribly loose and will not shift smoothly. i can't find anything in the manual on how to replace transmission fluid or what kind to get (if that is the problem).

did you let it warm for a while, i know this is not the best for the engine.... but 4 weeks would seem right to let it warm a bit?. From what I can read it's manual, if you push the clutch and can't get in gear it's either the oil system or master cylinder faulty. From what I hear the brake and clutch system are somewhat together (never had to check:lol). I would let it warm push the clutch to the floor quite a bit to warm it up also and check if any change is observable. good luck