I will check out the spare tire area. Thanks for the tip. I am one of those that has had a macerator on my previous unit (Roadtrek 210P) for almost eight years. If you have trouble with the macerator pump or hose and you are camped, you will appreciate the "emergency" big hose. My Roadtrek did not have a backup system (ours was a 2007, later years one was added), so I made one myself. Macerator hoses crack and bust and boy that can be messy!! I can testify to that fact, believe me.
By the way, you can buy a fifteen foot water pond hose at HD or Lowes and it is perfect for a macerator hose. I replaced my original hose with one of them and used it for five more years. They cost less than twenty bucks and if you have problems on the road, offer a quick and easy solution to replace the hose. I carry a couple of 1" PVC flexible pipe connections with me, which allow me to cut and splice the macerator hose in case of a problem on a trip.
Paul