I have a 95 525i with about 160k miles. After getting the "coolant level" warning I checked the coolant and it was very low. I filled it up and the car was fine for a couple of weeks until I parked on an incline one day. I noticed a huge puddle when I got to my car and the "coolant level" warning came up again.

I assume it still leaks even when its not on an incline but it pretty much empties itself when parked on an incline. Does anybody know what the problem is? Also, how much would it cost to fix? Thanks in advance!