POD123

have owned a 98 terzo since june with fssh, after applying the handbrake if only at traffic lights, upon releasing it i get a whistling noise from the rear which eventually wears off just bloody annoying.a freind who worked for prodrive for three years said it was caused by dust in the inner brake drum,he stripped &cleaned them but the problem returned in a week, the cars just had its 75,ooo service and i,ve still got the same thing, any ideas????