leaving a car in gear when parked so it does not roll will not do any harm.. matter of fact in my state the traffice laws call for a car left along to thave the engine off, the car in gear and the emergency brake on.... i got a 96 contour and since new it had problems with backing up and making a moosing noise(not from under the hood, but the rear brakes).. i brought it to the dealer and they changed out both rear calipers(4 wheel disc.).. but the problem did not go away.. i think it was the cables on the emergency brakes holding the rear brake pads ON and when the E brake was released it did not fully let go so the rear pads were on slightly when backing??? so far no wear on the rear pads... i think when i do change the rear pads( i already changed the front pads and rotors), i will check the cables where they meet the rear wheels and make sure they got some good high temp. brake grease on the cable and see if that helps...
