Can somebody help me please

Hey guys,

Does anyone know about any Tutorials that show how to make a car drivable or re edit the prop cars step by step. I’m been trying to make this stupid car to make a drivable for Counter Strike but when i put the car in my map it disappear? not sure why? I’m using blender for this but still not working right. I also try that on blender forums but no reply yet please i need some help.