Ok, so recentley my rear brakes developed this odd problem. When the car has been parked all day and overnight in my garage (open garage) I get this grinding/scraping noise from the rear. It'll go away after I depress them a time or two. I just replaced the drums 4000 miles ago and I don't drive like a bat out of hell. It's especsially bad if the last time I drove it was in the rain or I washed it the night before. It's got 58K miles on it and I dont think the rear shoes have even been replaced. What could be the problem.