After deadening my doors, I shit you not, it improved my midrange/midbass x100. I sealed off all gapping factory holes,deadedned the crap out of it, and it sounds beautiful. Imagine having a POS sub enclosure, throwing 500-1000 rms to it. That enclosure has airleaks, it creaks and all around sounds like garbage. Now imagine a sub enclosure that is air tight, built to specs,and sounds really lovely. That there is the difference that deadening my doors made. Just look at your doors being an enclosure for your mids, treat them that way, and you will be very happy. The same goes for the rest of your car. It is not by an means a waste of money.