Just completed my new headliner install. I first put down (or should I say up), Fat Mat as a sound deadner & heat deflector, then I put up a 1/2" thick material normally used for seat upholstry (just bought 10 extra feet from the guy that reupholstred my seats) and then on with the headliner. The directions are fairly straight forward to install the headliner, except I started in the middle and pulled to the front and then pulled to the rear. The end result looks better than new and there was no need for a heat gone, etc to stretch the liner, as I managed to get it tight all the way around. Take your time and try to heat up the liner in the sun before you begin.