I dont have a clear answer for you, but I can try =P.
Assuming you would be the only person in the car. I would unfasten the extra seats to make room. It depends on your car too, in some vehicles that would not help at all.
For the livestock, I would pick up some styrofoam coolers, I think they are about 2 gallons, place your livestock in their, as many as you feel you can comfortably without hurting them. It also depends on what kind of fish they are,obviously some fish will not fit in those >.< Ducktape the lids on. Place those inside the tank. Put your equipment in the tank to hold your livestock in place.
Instead of trying to use rubbermaid totes to hold your live rock, consider using rubbermaid trashcans, because they are narrower and stand upright so you might be able to fit more in there. I dont know much about transporting live rock, but there are some good guides on it here. I believe it usually involves wrappings pieces with newspaper dampened by your tank water.
If you have to include the stand and you have luggage rack, consider putting it on there. Or if you have a bike rack on the back, you could probably fit it on there? If you give it a shot though make sure the stand doors are fastened down
I've never had to transfer a tank that large in a station wagon, luckily I've always had a truck....so you can take it for what its worth, hope it helps.
