Anyone carry a "temporary use spare" in their car?

No kidding, I have 2 of the jeep xj donuts in the well of my duster. I think they stick up higher than the floor. I don't have the tire cover or mat anyway. If you did I think you could just make a spacer out of rigid foam to make the floor level with the tire.
I measured this donuts yesterday they are 125/90/16 about 24 1/2. My tires are about 25 1/2. Not ideal but I think it could get me out of a jam. And yes I do carry AAA.