They should, though. Chicago to LA via 66/40, then up the 1 to SF, was probably the most fun I've ever had in a car.
It is pretty rare. Just about everyone told us it was a dumb idea. As big a proponent as I am, I certainly wouldn't recommend anyone buy a car around being able to do that, though.
If interstate cruising is the most fun you've had in a car you apparently aren't very flexible.