just bought an '88 325ic and the previous owner had brakes installed by meinike. Will BMW sensors fit onto these pads? I ordered the front and rear sensors and one has a metal pin protruding from a black plastic plate while the other has 2 flat plastic plates. Why are these different and which goes on front? Also, my brake-light check light on the overhead panel is lit even though my brake lights are working. Any way to diagnose this, could it be a bad relay? Thanks, Kelly