Ive had good success with dynamat. I put a bit under my center console around the shifter after i installed my barton 2-post bracket. Its quiter then stock. As far as the suspension goes im not sure. I have barely any increased NVH from my suspension work minus a liiiiiitle bit from my lcas and brackets at low speed with the windows up and radio off.
2014 Mustang GT Base MT82 -Stock 3.73s, Roush axleback, Steeda 93R tune, Steeda Hi-flow X-pipe, 19" Charcoal AMR's, smoked front and rear side markers, 20% tint, quarter window louvers, Steeda Ultralite springs, Koni Str.t shocks/struts, MM camber plates, J&M adjustable panhard bar, BMR LCAs and relo brackets, Barton shifter and 2-post bracket, Black Modern Billet Grilles