I know that you can get the sky caps to help with luggage through the airport, but I am not sure about once you get to the tram. You might consider having one of you stay behind with kids and luggage and the other go pick up the car - might be less hassle - then the one with the car can just circle pack around and pick everybody up.

Check Travel Zoo and see if good rates come up for the Clement, the desk clerk told me they are on there quite frequently when we stopped by the hotel. ***kim***

I would definitely do what november_moon suggests - one of you go get the car and then come back to pick up the others. It's an easy on/off the freeway to circle back (one exit).