This is meant to be a no assembly, no supports toy car that can be done in a single print. The size is based off of Matchbox and Hot Wheels cars and I am including the SketchUp file to encourage folks to do a Christmas hackathon along with me. The axle is trapped and the wheels are tapered so it shouldn't need supports. Also we just added a space for some pennies to add weight for that orange hot wheels track! New Version: Version 1.8 LEGO-Fin : The kids wanted to make a space for a Lego Minifig to fit so we squared off the penny hole and how you can choose, pennies or Lego characters. Version 1.8Fin added a version with a FIN! cause they make everything faster :) Version 1.8 now should fit pennies. The earlier version only fit dimes. Also we made the car more flat so it can be customize easier. Note: the 1.3 version will allow US dimes to fit but they will fall out when flipped over. The 1.8 version holds pennies and you will not get them out easily (hence the hole to push them out-when it's time to recycle). Print takes about an hour. Add pennies and start playing! PLEASE post a MAKE and feedback. :-) The girls and I are hoping to create a set if I have time this week. First Test print, and the wheels roll! See here: https://www.youtube.com/watch?v=VTn75fFcnG0 Merry Christmas!Currently printing with a Makerbot Dual, Standard resolution(0.2), 2 Shells, and 15% Fill (but will use 50% later to make it super solid).