Re: myCar.acUnit.SwitchOn();

I know the subject of the post is a bit cryptic, but here is what I'd
like my code to look like:

int main()
{
  Car myCar;
  myCar.Start();
  myCar.acUnit.SwitchOn(); // invoke TurnOn(), method of class
AC, which is a member of class Car
  myCar.acUnit.SetTemp(75); // invoking SetTemp(), method of class
AC, which is a member of class Car
   ...etc...
 myCar.Stop();
  return 0;
}

How should I declare classes Car and AC?

The way I see things, this is what the declarations would look like:

class AC
{
  public:
     SwitchOn();
     SwitchOff();
     SetTemp();
     GetTemp();
  private:
  ...etc...
}

class Car
{
  public:
     Start();
     Stop();
  ...etc...
  <access_specifier>:
     AC acUnit;
     Engine engine;
  ...etc...
}

What should <access_specifier> be so that I can invoke AC's methods
from a Car as outlined in the code above?