how effective really is flashband for sound deadening? i checked their web site and it's used for roofing purposes! i'm surprised pwede siya for sound insulation.. ok ba ito? or i'm better off with some of that "Wurth" material from the audio shops? (magkano ba yun?)

i'm just annoyed at the level of road- and engine noise of my car. this is a mazda 626! but it's a h*ck of a lot noisier than my friend's city.. nasisira yung wanna-be-luxo-car image :D

i don't intend to strip the doors etc.. madugo siguro yun. pero some sound insulation sa may engine firewall and on the floors.. will this help? i have a small budget and not much expertise, pero i will DIY it. what's the best approach? thanks..