Finally did it. Gutted the interior of my Pilot and put sound deadening material in it to help with all the background noise that got on my nerves. We bought an EX 2WD and it became obvious after we had it home that it needed some help. The dealer tells me that the EX-L and higher models come with acoustic glass. Mine did not. I've also read some posts where others have speculated that the Touring and Elite models have extra sound insulation. Don't know about that, but I can tell you from personal experience after removing all the trim, seats, headliner and carpet in my Pilot that Honda did not put anything very impressive in the "plain Jane" EX model I bought to keep the vehicle quiet . We simply did not want leather seats, or else would have purchased a higher-end Pilot. Now that I'm done, I like the results. A cheap, free decibel meter app that I down loaded on the iPhone only shows a 1-2 dB level reduction in noise, but all that non-stop, irritating background drone noise is gone. Glad I went to all the trouble.