The National Automobile Dealers Assn. Used Car Guide Co. and auto dealership distributor The Reynolds and Reynolds Co., form an online prototype joint venture to offer retail and trade-in transaction data from dealers to consumers looking to buy or sell a used vehicle.

The prototype provides market-based detail about used vehicles in specific regions, says a spokesman for the joint venture. Reynolds gathers data on used vehicles from new car franchises in the U.S. The data is updated on a weekly basis and consists of trade-in and retail pricing, year, make, model, mileage and region sold.