Which document must an auto salesperson provide to a customer before completing a sale?

The correct answer is the Vehicle Purchase Agreement. This document is essential in the car sales process as it outlines the specifics of the sale, including the agreed-upon price, details about the vehicle, and any additional terms related to the transaction. Providing this agreement to the customer before completing the sale ensures transparency and clarity regarding the sale's conditions, which is crucial for customer trust and satisfaction.

The other options, while important in different aspects of the buying process, do not fulfill the specific requirement of informing the customer about the details of the transaction in its entirety before finalizing the sale. The Sales Contract is often part of the Vehicle Purchase Agreement but lacks the comprehensive nature of outlining the entire purchase transaction. The Finance Agreement is pertinent for customers opting to finance their purchase but is not required for all transactions. Lastly, the Dealership Warranty pertains to the coverage provided after the sale and does not serve the purpose of detailing the purchase terms prior to completing the sale.