Installed the Dynamat Extreme door kit recently in my 2013. The install was not a hard install, but, it does take time to get it right.
I am IMPRESSED! I only had stock speakers in for 1 day, but, man did it make a difference. Much less road noise and it deepend the sound of the stock speakers.
Highly recommend this upgrade. Amazon has them for just over $50.
2013 Black GT
JLT Cold Air ~ Bama Tune ~ SR Lowering Springs (1.4" Drop)
MMD Classic Quarter Panel Louvers ~ MMD Side Scoops
Kid seat in the back