Roadmaster Spare Tire Carrier

A mounted spare is only good part of the time as front and rear wheels on most coaches have a different offsets and you can't interchange them. You would also need the tools to change the tire. When we went to Alaska we carried a spare tire in our toad, (no Wheel) because getting road service is possible but finding the right size tire could leave you stranded for days. I would not carry a spare exposed to heat on the rear of a dp.
imho