Cigarette burns on the roof of a car are considered permanent damage. They cannot be fixed without having a specialist who repairs car interiors replace the material from the entire roof with new cloth or vinyl. However, you can conceal them with a patch of matching cloth.
Slice a small patch of cloth that is only slightly bigger than your cigarette burn. Most cigarette burns are the size of a pencil's eraser, so the patch must be small in order to have an inconspicuous repair. Your patch should not be bigger than a dime.
Dab a tiny amount of your solvent-based glue on the cigarette burn. Make sure the glue doesn't bleed beyond the perimeter of the burn.
Apply your patch directly to the burn. Hold firmly for about three minutes to make sure that the cloth has adhered completely.
Spray the area with your flocking glue. This is important to help seal the area. Make the spray area small to keep the patch inconspicuous.
Apply a modest amount of velour topcoat to the area to prevent it from becoming sticky.
Ideally, you need a piece of cloth that matches not only the colour of the cloth on the car roof, but also the material. If the roof of your car is patterned, use coloured pencils to mimic the pattern so that it matches the rest of the roof. Do this before you use the velour topcoat.