Zero car

A zero car is a car used in rallying to open the road for the competing cars.
The zero car has two main purposes:

so that the public is not surprised by the first car and
so that its driver can warn the organization if there is a problem on the stage.

Originally only one zero car was used. These days it is not unusual for a rally to have two or three zero cars. The 000 and 00 cars are sometimes called safety cars. The cars are driven through the stage in order from 000 to 0, with the 000 car going slowest and the 0 car going near race speeds. The 0 car is the last car to drive the stage before the competing cars.
The drivers are usually retired rally drivers. The cars can be ordinary production sport cars, old rally cars or even new models. The driver and co-driver wear normal safety equipment. The zero car is usually driven at almost rally pace.
Zero cars should not be confused with the organization car or the FIA inspection car, which also pass through the special stage before the rally cars, but are driven much slower.