For you folks who want to start carrying a spare for their Class C, but also want to maybe carry along something else that requires use of the rear hitch ... you might want to consider a front hitch, in addition to the one in the back.
My preference would be to add a front hitch so as to either A) not have to carry a heavy thing that mounts in the back hitch or, B) not have to use a long hitch extension in the back that sticks out quite a bit for the carrying of two things. For a Class C, too much weight way at the back hanging off the hitch can negatively affect steering.