This is a little thing, but I am curious. Periodically, while driving in my 1987 325, the car makes three clear tones, like a warning sound of some sort. It is not the key-in-the-ignition sound or the radio alarm sound. I think the electrical system in the car is pretty weird in general, so it may just be a computer glitch or something. I also have a sneaky suspicion that it is some sort of fuel level warning, but it doesn't seem to do it regularly. I don't have an owners manual to look in, so I appreciate your insights.