This Instructable will provide a simple set of instructions to build the ambulance shown here. The parts required are included in most basic Lego sets. Color is totally up to you, but the colors shown here were chosen to look more like a real ambulance.
2 - axles with attached tires
2 - 1x8 bricks
5 - 2x4 bricks
1 - 2x4 windshield (2 bricks tall)
1 - 1x2 clear window (2 bricks tall)
4 - 1x6 bricks
1 - 1x4 bricks
2 - 1x1 bricks
Step 1: Basic Chassis
Attach the two 1x8 bricks to the axles on the outermost pins, closest to the tires. The axles should be at the very end of the pieces so the 1x8s don't hang over at all as shown here.
Step 2: Chassis - Cont'd.
Place two 2x4 bricks on the two exposed pins in between the 1x8s. The ends of the 2x4s should be flush with the ends of the 1x8s to form a solid rectangle on the axles. This surface will form the body of your ambulance.
Step 3: Windshield and Window
Now place your 2x4 windshield piece at the extreme end of the chassis, either end will do because they are currently the same. It will span the entire chassis. Then place your 1x2 clear window piece at the opposite end of the chassis on the middle 2 pins with the flat surface flush with the edge of the chassis. Make sure that the windshield and window are mounted correctly as shown here.
Step 4: The Cabin Walls
Now take your four 1x6 bricks and place them adjacent to the rear edge of the windshield and flush with the edge and rear of the chassis. The 1x6s should also be adjacent to the window at the rear of the chassis. After all four bricks are placed the windshield, side walls and rear window should all be at the same height. For this example red 1x6s were placed on top of white 1x6s.
Step 5: The Cabin Roof
In this step you will cover the cabin created in the last step. Place a 2x4 brick across the top of the windshield so it is sitting on those 2 pins, and also on the first pin of the 1x6s from the prior step. Then place two more 2x4s adjacent and flush with the first until there is only a 1x4 area left in the rear above the window. Place the 1x4 brick across this area, again flush with the other bricks. This should have created a large rectangular roof as shown here.
Step 6: Emergency Lights
In this final step you will place the 1x1 blocks on the 2x4 from the previous step. Place the 1x1s in the second row back from the windshield on the middle 2 pins. Typically red and blue would be used for this to lend the appearance of real emergency lights, but any colors will work.
There is your completed ambulance! Now place your driver in the cabin and have fun driving your new vehicle!