Zenn...dynamat very exp...but i understand if want the best...cant see $$$ heheheh. i read many reviews that 2 layers of raammat = to a little better performance compared to a single layer of dynamat xtreme. if not mistaken...sika is a lot thinner than dynamat n raammat. i bought 6pcs in the past n did up my seats n floor pan but to be honest...i dont feel any difference.
Izso...i immediately though of stone temple pilots when u said STP ahahahha. reading up on it now but not many independent reviews on it ler. u referring to STP BOMB rite? 4.2mm thickness n each sheet at 265X367MM? 1 box definitely not enuff for firewall n whole floor pan tho...u know the price? i sent them a mail but dun expect an answer so soon...
well, i believe bomb are not required for firewall, i suggest u use stp gold for it as it's thinner and easier to apply. for the extra money, u should add another layer of noise absorbing material...dampening alone wont be enuff for firewall and floor pan.
for pricing, u can call me for comparison.
if u are buying the bulk version, firewall alone will use max 3-4pcs depend on ur car. most car will use 3pcs. i do sell seperately if u interested. thanks