ok whats the best thing to use when sound deading ya car, cos ive got two 15" kicker new l7s and a directed 2400d amp running at less than half power and my cars rattling like crazy! ive got sum dynamat coming but its so expensive! can ne1 tell me anything that works well but is a little bit more cost effective. im going to be using sound deading mat and then filling the rear quarters, doors boot and roof lining with expanding foam. it needs it, the subs r jus killing my car!