Hell no! I did my whole truck in that BS... Your friends must have never used real deadening then.
My car is done in AlphaDamp. Good stuff. Plate is deadened and I have a piece of foam behind it. Only thing that rattles is my spoiler....
10 Coupe 5sp
Pioneer 80prs/2 Tantric SHD 21"s WALLED/5 90AH batteries/DC power 270XP Alt/Taramps T20.2kw/DSP3000/DSP1600/TS800x4/4 Crescendo UN-10"s/2 FT1 tweets
Projector retrofit with 50 watt morimoto.