VIN authenticity can be tied to payment milestones, but each milestone must correspond to objective documentation. List in the contract the cross-checked results of VIN history, physical vehicle inspection, title documents, and maintenance records, along with the reviewer; release the corresponding payment only after the documents pass review. Splitting payment into installments without evidence conditions still will not prevent vehicle history, mileage, or structural condition from being unproven by a single photograph. Apply the principle that missing database records do not mean the vehicle has no accident or repair history.
For supporting evidence, see What is a pre-shipment inspection for used vehicles?.