A good adhesive for headliners is the 3M 8088, General Trim Adhesive. It has an adjustable spray nozzle, and goes on in a nice lacey pattern. I have used it for several years, and haven't had any problems with it. The 3M 8090 Super Trim Adhesive works as well, but does carry a much stronger odor that sometimes stays around longer than you would want. They are both available at Wal-Mart for under $10.00 a can, which is cheaper than at the local auto parts store.