Choose a template, and create and download your document for. For example, an enforceable bill of sale: Date purchased, vehicle’s model year, make, model and serial number; You will also need to either provide the buyer with your valid certificate of inspection (coi) or inform them they will need to have the vehicle inspected before they can register and insure it. When a vehicle owned by an estate is sold to a third party, a bill of sale (signed by the estate executor or disposer) is required, in addition to the other documents listed here.