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Further info on Cascade damping/barrier materials: www.cascadeaudio.com They have application guides, how-to's, etc. Where to buy: Plenty of online retailers (partsexpress, mmx, etc.) sell this stuff. Your best bet is to search by product, as different retailers will have the the best price at any given time. How to install: I have to 'fess up and admit that I have a previous (BH) gen Legacy wagon, so my experience may differ from that of a BL/BP owner. For the complete soundproofing treatment (floor, doors, roof), you will have to gut your interior. The process is not difficult, it's just time consuming - this is why a shop will charge $$$ to do this for you. You can break the job up into two stages: 1) passenger seating area 2) rear cargo area It is vitally important to have proper disassembly/reassembly instructions beforehand. This is especially true if you have side airbags in the front seats! If you have not already done so, go to techinfo.subaru.com to download the complete service manual. For $35 you get a 72 hour subscription, which may be enough time (over a long weekend) to poach the entire thing. You can browse the TOC without a subscription; you just can't see the actual PDF files. General hints: Take the time to "understand your trim fasteners." Some can be pried out, some must be unscrewed. Most screw type plastic fasteners take a #0, #1 or #2 Phillips head screwdriver. Use the proper bit to avoid mangling fasteners. Have several thin-blade flat head screwdrivers on hand to help with prying. A right-angle (ratchet is best) or stubby #2 Phillips screwdriver may come in handy for tight spots. Vinyl barrier material (VB4) is half the price of the lead/foam stuff (VB3), but it's really only useful for FLAT surfaces. Any kind of curvature (wheel wells, tranny tunnel, rear underseat, etc.) requires the flexibility of the VB3. Plan on two packs of VB4.5 and 3-4 packs of VB3.5. Get a single pack of VB2 (not the thicker VB2HD) for "taping" pieces of barrier material together. With damping materials, the adhesive gets "old" if it sits too long (6-12 months) so buy it as you need it. Covering the entire cabin floor is a good 2-3 day job for 1 person. Either budget the time, or find a competent friend or two to help. It is possible to drive around a gutted car, but it is not pleasant, and the car will be vulnerable to water leaks in the door pillar areas. To avoid wasting material, you should ideally construct templates using large sheets of paper. Cover the target surfaces with the paper. Hit flat spots first, then progress to the curvy surfaces. The paper will help you figure out the proper piece geometry for covering curved areas. When you have your templates figured out, arrange them on the barrier material like you're completing a jigsaw puzzle so as to minimize gaps between pieces. You must try to achieve near total coverage when using barriers, otherwise the noise will "find a way around" the barrier. Try to minimize the number of cut pieces, and make sure that each piece "mates" with adjacent pieces. This is largely a "trim to fit" process, which can be minimized by good templates. Cover each joint with VB2 "tape". For funky curves, and to hold pieces in place, use 3M double-sided foam tape periodically to "tack" the barrier to the body. The floor carpet is heavily padded in some areas, and the padding plus the barrier may be too thick in some spots. This may prevent trim panels and even the car seats from fitting properly once reinstalled. Likely trouble spots are the seat mountings, the rear cargo area quarter panel trim, the tranny hump between the front seats, and the cargo floor. TEST FIT PANELS AND SEATS EVERY NOW AND THEN to make sure that you remove enough barrier and/or carpet padding in the tight spots for proper reassembly. THE SEAT MOUNTING LOCATIONS ARE TRICKY - MAKE SURE YOU CAN PROPERLY THREAD THE SEAT MOUNTING BOLTS, OR YOU WILL STRIP THEM AND THE NUT WELDED TO THE BODY ($$$ TO RETAP OR REWELD A NEW NUT).

For floorpans and the tranny hump, your best bet for overall road noise reduction is to use a "barrier" type material. Unlike damping sheets, which essentially add additional mass to panels and thus lower the frequency of vibration, barrier materials act to acoustically isolate/decouple. The idea is to have a high density amorphous material which absorbs incoming acoustic/vibrational energy, and suspend this material between layers of closed-cell foam. The inner material is thus unable to retransmit any vibration to the cabin interior. This is similar in principle to the thermos. The newer generation Legacies already have asphalt-based mats applied to the floorpan areas and foam/fiber absorbers glued to the underside of the floor carpet. Adding more damping materials here is already testing the law of diminishing returns. I laid Cascade Audio VB3 and VB4 from the front footwells back (floors, tranny hump, wheelwells), which significantly reduced road noise. These are non-asphalt-based materials (no smell) and are only 0.25" thick. The Subaru uses "quiet steel" for the firewall, which is just two steel panels sandwiching a central butyl rubber absorber; barrier material behind the dash would probably have been overkill. I had also tried this on my previous econobox (no factory damping), and the difference was much more noticeable. For doors, trim panels, and the roof area, damping materials are the way to go, mostly because 1) these areas have much tighter space tolerances, and 2) you're now dealing more with panel vibration issues as opposed to "noise from without."