Here is the Simple tutorial on using Zebra Stripes.
Zebra Stripes work like if you model was enclosed in a cube with stripes on wall. If the surfaces are tangent to each other than the stripes will too.
Open the car model
Under Evaluate tab choose Zebra Stripes.
Keep the default settings and zoom to a selected area.
As you can see that the stripes are not continuous, that means the surfaces are not tangent. So there will be a higher drag force on these areas.
Now again Zoom to Selected area on a different place.
This time we can see that the Stripes are continuous that means the drag force effect will be minimum. Zebra stripes are usually used in basic surface evaluation for more advanced evaluation you should learn Flow Simulation for external system.