This invention allows a customer to use a handheld PDA device to recognize the vehicle identification number of a vehicle for sale at a dealership's lot. The PDA then transmits over a wireless local area network the chosen vehicle identification number to a host computer server which accesses hosted database tables containing the vehicle sales price information, normal financing rate and term information, the manufacturer's incentives applicable to that vehicle including cash rebates and low APR offers, and the personal customer information necessary for calculating that customer's monthly payment estimate. Several different methods of calculation as necessary are performed, and the preferred estimate amount, typically the lowest payment estimate, is transmitted back to the PDA for display to the customer. In the event of a net cash sale, the net price after all applicable rebates, coupons, discounts, and incentives is transmitted to the PDA rather than a payment estimate.