Haven't used Eastwood, limited experience with Dynamat, however I have used other brands of panels.
I will give you the short and long of it:
Cleaning and preparation of the surface is essential to any of the peel and stick products. A small roller applies more pressure to the part, getting that essential bond.
Remove any dust and use a two cloth system for wiping the panel with a paint prep solvent is a good idea. Cutting the panels into smaller, easier to work with pieces is best when dealing with deep formed panels or a complex shape.
A heat gun is an essential tool.
If you want increased thermal performance on the roof panel in addition to reducing sound transmission, you could apply a 1/4" bubble insulation with a urethane adhesive. [ instead of $$ on peel and stick panels ]
http://www.homedepot.com/p/Reflectix-48-in-x-25-ft-Double-Reflective-Insulation-BP48025/100052556
Sikaflex 221 is a moisture cure urethane adhesive that has a high viscosity suitable for such an installation. Butter up one side of the insulation and stick it to the roof panel. Apply aluminum HVAC tape to edges and joints.
I have about 4 tubes of Sikaflex in each of my doors, along with a few on the roof and back cab wall. Thermal emissions in the winter are low, in fact with the heat on high, snow does not melt off the roof panel when the vehicle is stationary.
Closing the doors is reminiscent of an old 70's Cadillac.