headliner doesn't usually dye well, it has a tendency to get stiff and shitty. As for the carpet, a cheaper route is to go to the grocery store and buy black Rit dye, its a concentrated powder you mix with water. Remove the carpet from the car for best results. Wearing gloves, spray the water/dye mixture onto the carpet utilizing a spray bottle. Spray it as evenly as you can, then rub it all in with a rag and allow to dry. This method doesn't give your carpet the hard cruncy feeling that an aerosol does, and a box of rit dye is like $3.50 as opposed to $10 a can for SEM dye.