Yes. They fit up to six passengers. However, both of the car seats have to go in the middle row. One adult can sit up front in the passenger seat, but at least one of your adults will have to use the third row. This isn't an issue if you draw a newer vehicle (I think the new ones are Suburbans), but in the older ones (I think the original vehicles were Traverses) it can be a little awkward to get back there for someone who is larger or has mobility issues.
Thanks. We definitely had the older vehicles to and from the airport early this year, but on our more recent trips we've been in the new ones. I didn't realize that they changed the fleet over all at once.