UnityCar + Realistic FPS Prefab problems

Hi! I have UnityCar and Realistic FPS Prefab. Both works great… separated. I am so begginner and I want to make player get in and get out of the car. If both prefabs are active, I walk and ride in same time. How to make player get in and out of the car?

if(inCar)

https://unity3d.com/learn/tutorials/modules/beginner/scripting/if-statements

disable

https://unity3d.com/learn/tutorials/modules/beginner/scripting/enabling-disabling-components

https://unity3d.com/learn/tutorials/modules/scripting/activating-gameobjects

You will really benefit from some tuts to advance your understanding of the scripting tools.