start off where the speakers are, if u run ones in the doors, take em out, take off the plastic off the door, clean it up thoroughly, then use that plastic incase you need to wrap something, like a tie to something or whatever, clean the metal with alky then put the mat on the door and warm it up when its on with a heatgun or a hairdryer. if the weather is nice, leave it on a blacktop driveway for like 45 min so its tacky. once uve covered the door, cut the hole out for the speaker and put in back in. you can do some in the trunk, tank all the panels off and dont forge t the hatch. yank them panels off and cover it. if u want, you can do the roof under the headliner, but some people have problem with insulating that, some may come off in the summer heat, so im not making any promises or anything, but it or may not. ive personally never used fat mat, but m considering it, because its cheaper than dynamat and i want to do the entire inside of the car.