We carry an extra spare for the car, 2 spares on the car and one on the trailer, which makes 3 spares, been down the road of having two punctures, thankfully we had the extra, a total of 3 punctures for the trip, all in the sidewall, so no chance to fix with plugs, not that concerned with punctures on the trailer, I can still tow it with a flat if need be.
Baz.