I don't carry a spare ,jack , jack handle, or lug wrench in my C1. It is not a NCRS car. The trunk mat and the plywood cover would have to be pulled up to check it. The regular car shows I take the car to ( pre covid) do not do that. If I did carry a spare, I would carry my electric impact and a bottle jack. The reproduction jacks have that disclaimer because anyone who has used those types of jacks, even the originals provided in many cars back in the day, found that they had a tendency to fold over, especially if the base was on uneven ground and the car not securely blocked.I have AAA and Hagerty, both with roadside assistance i.e. flat bed. If I had a flat tire on the rear, I would have to move a front tire to the rear and put the spare on the front because the spare would be a couple inches smaller than my tires. I would have to carry blocking etc. in order to do this.