Squeaking noise

[bushypad]

My car keeps making a squeaking noise everytime i go
Over any bumps.. The noise sounds like its coming from the rear.. I had an exhaust fitted few months back.. Also i was in traffic and moving off slowly and heard an awful screeching noise sounded like metal scraping could it just be a stone stuck in brakes

[bigmig95]

I've had the screeching from both front and rear at both slow and moderate speed.  On all occassions with my car it's a stone stuck between the brake disc guard and disc itself.  Right pain in the  and damn noisy