I just bought a really nice 1989 325is. When I bought the car the ABS and Brake lining light was on. The previous owner said he just replaced the rotors and pads. I already bought the front left and rear brake lining sensors. How many ABS sensors does this car have? I am waiting until I have everything I need before digging in to fix both probs. Also, is there a good source for new or used ABS speed sensors? Thanks in advance.