Step 1: This is very easy is to draw. The first thing to do here is to draw a bubble like shape that is sort of flattened on the bottom. Then, draw a horizontal line going through the shape.
Step 2: After drawing you have drawn the frame for this police car, next, is to start drawing out the actual shape or outline of the vehicle which includes the windshield, hood, and door lining.
Step 3: Now add two vertical lines as shown to create place marks for the front side door. Then draw two circles for the side tires.
Step 4: The next thing now is to start drawing the rest of the car's frame shape including the body outline, tires, bumpers, headlights, taillights, and of course the hood light for the siren. After drawing all this, then add the detailing lines for the window framing, and side mirror.
Step 5: This is the last step, now draw the wheel rim design, and then add some minor detailing to the door which includes the molding and door handles. After that, add some line definition and detail to the hood and fenders. Make sure you erase the shapes and lines that you drew in the first step.
Step 6: Now, add color to this police car and you are done. All you need to do now is color in the police vessel and you're done.