Car dealership documents are legally used to document the sale of a vehicle, including the terms of the sale, the buyer and seller information, and the vehicle information. These documents are also used to register the vehicle with the state, transfer the title, and provide proof of ownership. Additionally, car dealership documents are used to document any repairs or maintenance done to the vehicle, as well as any warranties or guarantees that may be included with the sale. Finally, these documents are also used to document any financing or leasing agreements that may be involved in the sale.