Best results, in my opinion, would be, the entire door,and maybe give @KeepHopeAlive a heads up, and see if you would like to go the extra for the above best results of Insulation in plastic in the doors..Very interesting concept, and Im certain well worth the efforts..There is a thread about it on this site,under speaker installation you may want to look up and read..Yet, Id do as much deadner as you can afford and have the patience for..I wouldnt recommend doing the entire vehicle, if I werent going to keep the vehicle?sell in the next 2 yrs or ?Id prob just do as much needed for the speaker in place,..Just my opinion..Deff up to you and whatever you are willing to spend, and time spent/invest