Thanks
 

Thanks for your very thoughtful response. I tried the blanket idea and it worked! FYI I am returning to the audio store tomorrow and something is going to be done because I am pissed!!!!!!! I located a dynamat dealer and will see them tomorrow. Thanks again so much!!

I'm interested how this will go since they already have your money. Good luck as I'd expect little motivation to do anything for you.

Hopefully the audio folks will make it right. If they surprise everyone by pulling back the carpet in the hatch to reveal a full Dynamat job (I would be surprised considering your reaction to their work) your next step would be to wait and see how my Luxury Liner Pro works out. If it works for me it should work for you.

One bit of very good news is your positive response to the "blanket" test. This suggests that a solution to the problem is possible. I suppose that this is where some wise a** posts the following: "Problem solved: "The big Blankets-R-Us sale at the mall, the new hot mod for the 370Z".

Happy Motoring!

Ok, I just finished installing the Luxury liner pro and here are my thoughts:

Phase one:

Installed 36 square feet of Dynamat Extreme on the doors and hatch.
Cost: $140.00 from Amazon.
Weight: About 20 pounds.
Results: Significant noise reduction, the harshness of the noise significantly reduced. Tire and road noise significantly reduced, and the feeling that you are able to determine the exact composition of every road surface by it's overpowering sound is significantly moderated. The sense that you can hear EVERY grain of sand and every pebble that hits the chassis is almost gone.
Bottom Line: Great bang for the buck! The weight is not excessive considering the positive result. Probably good enough for most owners.

Phase two:

Installed about 20 square feet (2 1/4 panels) of Second Skin Luxury Liner Pro.
Cost: About $130.00 including shipping and a can of spray adhesive.
Weight: About 25 pounds.
Results: Additional noise and harshness reduction. Sand and pebble noise is gone. Changes in road surfaces can be noted but they are no longer annoying.
Bottom Line: Provides an extra level of refinement. Noise from the rear is no longer an issue, most noise is now from the front of the car. A moderate low frequency resonance/rumble over some road surfaces is now noted from the front of the car, apparently it was previously masked by the noise from the rear. It's not especially objectionable but it seems a bit out of place in the now, quieter cabin. I could have been very aggressive and installed even more material but I was reluctant to add any more weight. I think that most of the benefit can be obtained with two panels applied to the hatch floor and the wheel wells, about 80% coverage. I skimped on the rear wall of the hatch and I don't think it had any negative effect.

Notes:

Dynamat is fairly thin and easy to work with but in this application it goes on just about everything (about 90% coverage) so it is slow to install (about 8 -10 hours but I'm sure I could do it in about 1/2 that time now that I've done it once) the many pieces needed to do the job.

Luxury Liner pro is thick and heavy and not that easy to work with but I didn't try to apply it to every nook and hollow in the hatch so it actually went in fairly fast, about 4 hours. Avoid gaps wherever possible. Reinstallation of the trim panels is not going to be as easy as normal, I trimmed about 3/8" from the bottom of the styrofoam blocks surrounding the spare and it was still a tight fit to get trim panels back in place. Due to the bulk of the Luxury Liner Pro I had to pass on reinstalling the retainer buttons that the factory uses to secure the styrofoam blocks, they stay in place just fine without them.

More stuff:

I call this Chicken Soup because as they say "It couldn't hurt": After the original Dynamat I had some short pile (1/4" prox.) indoor outdoor carpet left over from another project so I applied it over the floor of the hatch and I stuffed some hollows behind and below the seats with polyester batting (basically pillow stuffing) and applied some of the Polyester batting on the backside of the hatch trims with spray-on contact cement.

Lay a thick soft blanket over the perimeter of the hatch opening to protect the paint from scratches. No watches, rings, bracelets, belt buckles, button front pants or pants with rivets, your paintwork will thank you.

Luxury Liner Pro is a two layer product. The soft side (feels like Temperpedic mattress foam) faces the body, the firm side is a dense vinyl and faces the interior. The material is bonded to the body with spray adhesive, one can seemed to be more than enough.

I found myself wondering if 3/8" rebond carpet pad could be substituted for Luxury Liner and still obtain most of the benefits, for those on a budget it might work, who knows?

Well that's about it.

ttt

it takes that long to install dynamat!! damn! is there a sticky on doing this yet?

By the time you remove the trims, install the Dynamat, and reinstall the trims the time starts to add up. There are several good threads with photos that cover Dynamat installation, usually in the DIY or Audio sections. First time is slow second time is fast.

Just to let you know.. This matter of the money I paid for the installation of whatever it was that did nothing, is now in dispute and Visa is withholding payment., I have a Nissan technician who has written a letter saying there was no noise reduction.
Meanwhile, I have an appointment Friday with a guy who does this kind of thing all the time including very high end cars. He looked at what had been done and tells me he can do the job correctly, for a lot less than what the other guys charged. Will let you know Saturday.

Sorry for the late reply. I used second skin damplifier pro with some LLP on top of that. Cost around $230 I think.

Well today I got the car back and things are fine! They found there was no.. NO.. sound dampening in the doors and so they added some and also added some to the area below the glass in the back.. the result is a a great reduction in the high frequency noise and i hear more of the deeper sounds of the motor..Like the purring of a tiger ready to spring followed by a full throated attack!!! Very good job..I have found that most of this noise occurs in cars with the Sport Package because of the larger tires..
Anyway .. all is well now and I might add that the guy that fixed it said he has driven many many exotic cars because a very high end dealer has him do work for him and he told me this Z compares favorably with Porsches costing 90K!!

The key is the upper area of the hatch and the doors... I could still do more but right now I am just going to relax and enjoy the car..

and one other thing to all the guys on this post..this is totally off topic but I will say it anyway.. get yourself a PSA test.. Prostate Specific Androgen.. An incredible One in seven to one in three males will find they have prostate cancer.. I figured it would never happen to me but it has..but I am lucky because i detected it early and am a survivor..if I had waited until I had symptoms I would be dead after two years of misery.. It was when I got this disease and was lucky enough to get it treated early that I said "F" it!! I am buying this car. NOW and that is the "rest of the story!" ..Perhaps I can save just one life by posting this...Spread the word..

RiCharlie,
So how much would it have cost to get the stuff installed by that shop in all the areas you ended up with in the end? I'm not interested in spending 2 days of my life installing this stuff but wouldn't mind the sound deadening.

Sorry to hear the news about your health......you might want to check out a new FDA approved therapy.....one I have worked on for a few years......it uses your body's own defence ......Approved this past June......by the FDA Made by DENDREON..........CALLED "PROVENGE"

Sound reduction
 

It cost $450 that that included labor and materials. I think it takes less than a day if you know what you are doing..

Cancer
 

Well as I said I am a Survivor.. the matter has been dealt with surgically but I just like to let all the guys know how prevalent this cancer is.. nearly 1 in 3 !!! and how easily it is detected and treated..but you have got to catch it early...

$450 seems reasonable. Anyone know a trustworthy shop around Albany NY or south of it?