Thank you for adding some comments to my thread, I've seen your name come up a few times, notably regarding foot pedals which I'm in the market for.
Dynamat and stereo. Coming from a Merc it was a bit of a shock to hear all of the noises that the Alfa generates, I've come to terms with it as in my mind I consider it a more sporty car and therefore the noises are a given element to owning such a car
Yes, I did test drive it without the stereo on but it was difficult to guage exactly what it would be like day in day out, besides unless it was a awful I decided I wanted to buy it as it looks so good !
After consultation with the Sound Gallery in Wycombe as to where the biggest sound deadning gains would be had we decided to tackle the doors and rear panels only. However they can put the stuff in the roof, bonnet, boot or other panels. Dynamat Extreme is the only material they deal with, in their opinion the others are not as good. As per my thread we discovered a few issues with the car at that time ! Fortunately they patched the damaged door card (sticking it together with Dynamat !). In the end they used up 4 packs of the custom fit Dynamat Extreme in the panels.
The cost of the materials came to 4 x £27.99 for the Dynamat, you can get this cheaper on eBay, I did recently getting 2 rolls at £40 delivered. The labour is quite intensive and the costliest expense, that came to £300. I did consider doing the work myself, using materials other than Dynamat and actually seeking alternatives (scouring the 4x4 forums, apparently Land Rovers are a bit noisy). Car Soundproofing - Vehicle, Industrial and Marine Sound Proofing - Noisekiller UK
is one such company.
Does it work ? Well, psycologically it works very well. That's not to say it doesn't work because it does, I think it depends on the noises from the car, where they are coming from and the coverage and quantity of sound proofing used. There still tends to be a lot of road and suspension noise so your car won't be whisper quiet. What Dynamat has tended to do is numb or deaden the sound so it's still there but quieter than before. However, I think the big win is that it stops a lot of secondary sounds because it inhibits vibrations.
Since having the Dynamat installed I've added a big thick rubber boot mat to the car (£40 delivered, eBay) and that has also made a significant difference in stopping the intrusion of sound. Based on that if you aren't going to put a boot mat in the car then Dynamat would probably help.
At the same time I had my JVC AVX2 installed complete with steering controls (note you lose the dashboard display part of the receiver) so it's difficult to say whether the Dynamat has made an improvement to the sound quality. However, the JVC is a significant improvement over the standard head which seems to lack power, again a disappointment as the Merc had amps and subs as standard. Bose ... I don't rate I'm afraid so I don't feel that I've lost anything there.
What do you think of your GT ? I'm quite smitten by the Alfa bug and think the car is actually quite good. I'd seen that some places are offering to convert the car to the Q2 LSD which I was thinking of but think I'll bed the car in first and save some money.