For Christmas, My kind wife bought me a couple of shooting bag rests from The Sprotsmans Guide.
I filled the larger one with about 25 pounds of rice and the smaller one maybe holds 5-6 pounds. I've taken the larger one out a couple of times now. Setting on the roof of the little S15 pick up, it is the perfect height for some long range plinking. It is long enough that I've not felt the need, so far, for a rear rest.
So far it's been a lot more convenient than bipods, and just as accurate.
Has anyone else tried one of these?