A few thoughts.
We have DirecTV at home. I have the tripod mount from CW for an extra dish that I have. We simply take one of our receivers from home with us on the road. We still get locals as long as we are in the Spot beam for our locals.
The tripod works OK. I feel it is more flexible that permanently mounting it on the roof. There is a homemade mount at this address:
(I think someone posted this before on this forum).