Update 3/3/09 For the leg construction, click here. The first step was to build all of the internal parts and the posts the attach them to. I would first build the part and screw on the attachment post. Trim the post to fit and then glue only the posts to the inside of the model. Unscrew the parts and the posts are permanently attached to the model. The posts were made using both square and round tube styrene. I first drilled out the square tubing the size of the round tubing and glued in the round tubing. I then tapped the round tubing using a 2mm tap for the screws I'm using. Here's a pic of the posts on the inside of the model. This is the "backbone" of the figure. It attaches to the inside of the rear bumper and incorporates the bots waist. Here it is as it sits in car mode. Here it is in bot mode. The waist rotates down and locks into place with the notches. The next step was to build the rear tire assemblies and points where the arm will attach. This part was pretty straight forward because there is a separate picture in the concept drawing. The parts attach to the backbone part and some inner door panel parts. I also built some tabs to keep the part from rotating in both modes. Here's a pic of all the parts included in the torso. I also finished building the hips and built a piece to fit in between the legs. This part also fills in a gap in the dash and will ultimately be where the windshield attaches. Here it is as it would sit in car mode. Here it is folded up as in the concept drawing. Here's a pic of the car mode as of today. And here's some pics of the bot so far. As you can tell, the roof is still attached. That's the next thing to do. Also, please keep in mind that a lot of the detail work isn't done yet.