Reflection: use dynamic type in C#

public class Car {
    public int Speed { get; set; }

    public void IncreaseSpeed(int value) {
        Speed += value;
    }
}            

var carType = Type.GetType("Vehicle.Car");
dynamic car = Activator.CreateInstance(carType);

car.IncreaseSpeed(15);
var speed = car.Speed;
//speed is 15