Parts List:

• Brick 1 x 1 (2)
• Electric Brick 2 x 2 x 2/3 with Wire End (1)
• Electric Rotation Sensor (1)
• Plate 1 x 2 (3)
• Plate 2 x 3 (2)

Notes:

• Remember that 5-long axle from Step 26?  The rotation sensor goes on that axle.  Now you can put the bush on the end of the axle.  Also, make sure that the wire for the rotation sensor goes up along the sensor (see that notch in the back of it?).
• When you connect a wire to the motor, make sure that you orient the wire like in the picture.  Otherwise, your scans will all be backwards!
• If you haven't figured it out already (notice the 1 x 1 bricks), the floating plate is part of a rigging I made to protect that bush from the wires.  Before you're done, you'll add another plate on the top and connect it to the car.