This is a shell to fit over a standard pinewood derby wood block. It is completely within the standard requirements for pinewood derby entries. It is a derivative of the "ActionCar pinewood edition" (thing 58010), with a number of changes: The wheelbase has been changed to match the distance between axles on the standard pinewood derby wood block. The profile has been thinned down to trim weight off of the printed part of the vehicle. Two recesses in the underside accomodate tungsten weights (fits the official cylinder-shaped weights). There are large differences now between this and the original ActionCar (thing 249), but the heredity is still visible. The wings3d file is included, and contains both the car shell model and a model of the pinewood derby block and wheels.This version of the pinewood derby action car needs very little work to the pinewood block. The block should be cut to a height of 10mm, and the front and back ends sawed short so that the front axle is centered 17.5mm from the front of the block, and the rear axle is centered 25mm from the back of the block. Print the piece with a low-density fill to keep down the weight of the shell, and be sure to add plenty of support material, since the piece is hollow and much of it is suspended over nothing but air. After sawing the block and printing the shell, place tungsten weights in the recessed areas in the shell to make up the 5 oz. vehicle weight limit.