There are a few things you can do to remove stains from upholstery in a car. The first is to use a mild soap and water solution to clean the surface. This will remove any dirt, grease, or blood that may have been on the upholstery. Next, use a cloth or paper towel to dry the area. Be sure not to get any water on the fabric or upholstery itself, as this could cause it to become ruined. Finally, apply an anti-static agent to the fabric or upholstery and let it sit for at least 30 minutes before using again.