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....
2010 Focus SE coupe 5 speed
Pioneer 80prs/AQ2200D/BK800.4/6 SQ pro mids/4 SQ supertweets/AlphaDamp/Projector retrofit/LED tails/ Walled with 2 DC 18"s
A lot of mods.