I would be interested in knowing this as well! We are thinking of doing one of 2 things. Renting in Buff, Flint, or Grand Rapids, leaving our car at the airport and drive one way and leave the car there and fly back. It is very expensive doing it that way! Being that we have 2 weeks for vacay this year, we thought about driving both ways, but only have a Chevy Optra with a 12 and 10 year old, it will be crowded. Anyhow, any and all infor would be appreciated as well!