I recently removed my door panels and installed b-quiet's vcomp http://www.b-quiet.com/vcomp.html
material behind the door panels. Here's a step by step:
1) First pic: Using a flathead screwdriver or similar tool, pry off the door handle cover. Pry down and out, this is easily the most difficult part of removing the door panel. Once you get the cover out a little ways, you may want to stick the pry tool down into the space created to get more leverage. There are three clips that hold the cover onto the handle, I actually broke one on at least one of my doors but it didn't seem to make any difference when reassembling the door panel.
2) Second pic: Using a phillips head screwdriver, remove the two screws that secure the door panel to the door. Pic shows the location of the upper screw, the lower is easily visible.
3) Third pic: Using a flat head screwdriver or similar tool, pry out the cover behind the door latch. Remove the screw.
4) Fourth pic: Pry off the cover at the top of the door where the door meets the A pillar
5) Fifth pic: Remove the door panel. There are several clips that secure the door panel to the door, these pry off fairly easily (or rather, the panel pops off pretty easily as you pry it off from the door. I was able to do this just using my hands and no other tools). Remove the wiring harnesses and door locking cables. Pic shows the door after the panel is removed.
6) Sixth pic: Shows the door panel once it's removed
7) Seventh pic: Shows the installed deflex panel mounted behind the door speaker. For an explanation of the deflex panel, visit http://cascadeaudio.com
For purchasing, visit http://partsexpress.com
(just do a search on 'deflex') or http://www.partsexpress.com/webpage....7&WebPage_ID=3
8) Eighth pic: Shows installed v-comp on door. I used Scotch brand mounting squares to secure the v-comp. It's kinda precarious, but once the door panel is reinstalled, the v-comp should stay secured easily with the pressure of the door panel. V-comp cuts easily with a good pair of scissors.
9) Ninth pic: Shows installed v-comp on the door panel. Panel is now ready for reinstallation. Notes: Make sure foam side of v-comp is facing source of noise. Also, you may need to do some additional cutting to make sure the door panel will fit and line up with the door handle screws.
Result: Significant reduction in road noise, well worth the time (approx. 6 hours for all four doors) and $ (approx 100 bucks for v-comp for all four doors, + the deflex panels for the front doors). Coarse road surfaces are noticably reduced, smoother road surfaces create much less road noise than before. The deflex panels seem to add extra definition and tighter bass to the sound, but this may be partly attributable to the overall reduction in cabin noise.