I have a family friend who is a mechanic who is repairing this for me. I am paying him. The leak was NOT coming inside of the car on the carpet and it was NOT fogging up the windshield, the heat still came out so I don't know where the antifreeze was going. I researched online and guys were saying a three hour job. But a guy I know said it would take eight hours. How long does it usually take? So I can pay him properly for his work?