设计一个汽车类vehicle，包含的数据成员有车轮个数wheels和车重weight。小车类car是它的派生类，其中包含载人数passenger_load。每个类都有相关数据的输出方法。在主程序中定义一个car类对象，对其车轮个数、车重、载人数进行设置并显示。

以下是Python语言的实现：

class Vehicle:
    def __init__(self, wheels, weight):
        self.wheels = wheels
        self.weight = weight
        
    def display_vehicle_data(self):
        print("Vehicle data:")
        print("Number of wheels:", self.wheels)
        print("Weight:", self.weight, "kg")
        

class Car(Vehicle):
    def __init__(self, wheels, weight, passenger_load):
        super().__init__(wheels, weight)
        self.passenger_load = passenger_load
        
    def display_car_data(self):
        print("Car data:")
        print("Number of wheels:", self.wheels)
        print("Weight:", self.weight, "kg")
        print("Passenger load:", self.passenger_load)
        

# 示例
car = Car(4, 1000, 5)
car.display_car_data()

运行结果：

Car data:
Number of wheels: 4
Weight: 1000 kg
Passenger load: 5