You can use the dead sheets that have an adhesive back and available from places like Brown Brothers. They are flexible and will mould to what you are sticking it to. Other is the acoustic matting [looks like a thin carpet] that you can spray adhesive on to stick inside doors. For the doors, i would put the sticky pads in the doors and use a sheet of acoustic between the anti rain sheet and door card.
To quieten the car right down, you will need to remove the inner carpet, and dead sheet the floor and panels. And do the boot and bulk heads
I thought though the Coupe was a sport's car, so should have some noise.
Andy.