I almost hate to say this, but it sounds to me like you need a minivan!

The new Grand Caravans have enough towing capacity to pull your Duster to he track, loaded with people. Put the seats down and you can haul 4' x 8' sheets of plywood inside, out of the weather! And they can pull down the same gas mileage your currently getting, and the V6 runs pretty good. There are reasons they are still selling them. Gene