I need a sales letter

Hi I am starting my window tinting services, I have purchased a work Van and all tools necessary already it’s a mobile service and I have set up a workshop in my home garage to tint car windows. I will also tint house windows and office. I will need a letter to get tint jobs from car dealership as a contractor and use Facebook market place to hunt retail clients with my competitive prices. I have 5 years experience in this field. I will be using Suntek films which is American made with lifetime warranty on films and lifetime warranty on installation against peeling, bubbles and fading. Let me if u can help plz