also check your brake vacume, thats what mine sounded like, just a scraping noise and only happend once in a while, then it happened everytime the car moved, here i busted the **** up when i backed into a mailbox :P that might be it, idk, im not real good with cars but its something to check

 

afetr driving the car for a few mins put your hand on the rim to check for heat. is the rim warm/hot compared to the other side?