I transported 12 adult discus in a 60g cooler with an air pump ran off a converter in the truck. It was a 10 hour drive across state and then they lived in the cooler for a total of 4 days because I had to stay in a hotel a few days before my house was ready. I drilled holes in the top for the air lines so I could keep it closed the whole time in order to keep the heat in ( I didnt use a heater, just changed out water once a day with warm water). One discus had some tail damage but has since healed up. The rest were just fine. I would think that you would have no problem at all in a car for 3-4 hours. Piece of cake.