I just recently a '95 Mustang coupe from a used car lot last week. It has been running great so far, but now I am concerned because sometimes, when pushing the clutch at the same time as the brake, it makes a LOUD metallic screaching/scraping sound. I think it has happened a few times when just pushing the clutch as well. When this happens, my lights will also dim and the radio cuts out (the gauge for the battery will also drop, but immediately comes back up as soon as the sound stops). I am not a car expert by any stretch of the imagination, but if someone could give me some ideas as to what could possibly be causing this I would be extremely grateful.