The wifes 2006 Charger Daytona has a spare in the well in the trunk next to where the battery in mounted.
My 2007 300 SRT8 has a foam block with compartments in it in that well.
That's where they put the air pump assembly and fix a flat goo.
There's no reason you can't put a spare assembly in
In my Scat, the well also has two large factory speakers. No room for a spare.
The spare tire kit from Amazon includes a carry bag. I’m skeptical as to quality, but we’ll see... haven’t received the kit yet.
I ordered a Wheather Tech trunk mat to protect the factory trunk floor fabric, and possibly keep the kit from sliding around.