My M5 had no spare. I went about 9 months they broke a wheel on a pothole when I was 90 miles from home. The inflator kit and sealant were of zero value.
This would have resulted in me spending 3-4 days at a hotel (while they ordered a wheel), getting a mismatched tire (they didn't stock PS2s) or renting a car for the trip and coming back for the car when repaired.
(As luck would have it a total stranger on M5Board lent me a spare OE wheel he had...)
I now carry a spare.
I will NEVER rely on roadside assistance as they CANNOT fix destroyed tires nor wheels.
What will take 20 minutes with a spare and jack turns into hours or days.
Feeling lucky?
A