About the combustion engine in the car, yes it is not necessary how it functions to drive a car, and this answer is from what you said in the previous comments in this thread.
Your recent replies here indicates you agree 100% that it is not necessary to see something to verify it exists.
I will give you simpler questions:
1. If you do not know how to write English does this mean there is no English language?
2. If the evidences that there is a country called Australia not with you does this mean this there is no country called Australia?
See Thelonius when you said no body understand physics quantum, this means that quantum physics can not be used to explain how things work, a man with a good way of thinking will refer to things which have an explanation and will not refer to things which do not have explanation.