I don't have a roof rack; but I see people putting bikes up all the time. I think there is a technique where you open the car door and then use the door jamb ledge as a boost if you aren't tall enough.
I have hitch-mounted rack. It was no small task finding a hitch for my VW GTI but I'm glad I did it. I can lock the hitch to the car and lock the bike to the hitch.
With a Tribeca ... can't you just put the bike in the back of the car?
I'd rather be sitting on my bike thinking about God than sitting in church thinking about my bike ...