there is a crap load of sound deadening material under that carpet. a heat gun and a pry-stick would work. the adhesive is relatively new so use some goof off or if you want to go hard core xylene and a rag and a respirator.
also remove all the seat belt points as well.
09 335xi Sedan
03.5 E46 M3
01 Porsche 911 C4
87 528e 5sp