Hi everyone. I'm slowly getting my system pieced together, and had a question about the rear wall of my Ext. cab Silverado. I plan on mounting my amps and the brains for my IVA-D300/H701 back there on a piece of MDF. My question is, should I put sound deadening on the rear wall and then mount the MDF on top of it? Or should the MDF just be attached to the steel?