i have a white leather headliner in my car and since i put in a system it started saggin and fallin down i bought several different adhesives but none seem to hold it on is there a special on i need to use??????????????

there's a heavy duty one. leather are heavy so you gotta spray alot more than fabrics. works very well but you need to do it quickly before the glue dry. like spray 1/4 of the headlinear with at least 4 coat then immediately lay the leather. if all fail, shit you could use the goddam gorilla glue it's not going to show thru the leather.