There is a relatively large scope when it comes to the types of vehicles that can be used by driving instructor schools and to take a driving test.

There are some exceptions to this rule for cars that would stop an instructor from having complete all-around visibility, but for the most part, a driver and an instructor can use any car they feel comfortable in.

However, one addition that tends to be in instructor cars that is not necessarily a requirement is an extra set of pedals on the passenger side.

This is known as dual control or dual-pedal controls and allows for an instructor to take control of either the brake or clutch as required, as well as having a handbrake and a rear-view mirror.

The main reason for this is safety; new drivers are still learning the basic functionality of a car, and the first time they take to the road there is a chance that they could make a mistake. 

Dual control stops that by taking over the controls as and when needed.

This is not a case of mistrust but often the opposite; many learner drivers feel more comfortable and confident doing more difficult manoeuvers in real-world situations if they know that the instructor is there to take over if they get stuck or in a dangerous position.

In practice, this is often when they need to be used least. Driving instructors will typically guide and advise, only taking control when it is an emergency situation. As a learner gets better, they stop being used entirely.

Of course, an instructor will then need to explain why they used it and the potential consequences if they did not do so.

Dual control cars are a legal requirement for motorway lessons, due to the speeds involved and how many drivers tend to use a motorway at a given time compared to the average road.