I need two car transfers to the airport. I assume you mean one from the airport to your hotel when you arrive and one back to the airport when you leave.

I think what you're looking for here is "I need two cars transferred to the airport". You could also say, "I need to transfer two cars to the airport", talking about something you need to do in the future. Hope that helps! :)

I need two car transfers to the airport, if you are going to the airport and need to take 2 cars to do come there. I need two car's transfers to the airport, when you are talking of car's pieces (transfer case by example) that you need to send to the airport (place) as a order.