Regarding flats, on a road trip from Ma to FL, near Jacksonville FL.
I used the TESLA app and was back on my way in 4 hours.
Not much fits in the fronk, I dont think that a bare rim would fit.
A tesla tire for the M3 is HUGE. If you do that be sure and chain it down,
it could become deadly missile during quick deceleration.
I've had thoughts of adding a luggage carrier, and putting one
up there, but there is a lot of glass up there.
Glass, heavy tire, what could go wrong ? Never did it.