[Giller]

No, don't believe Porsche offers RFT - but they don't offer spare tires, just the compressor and fix-it kit.

The vast majority of car buyers never get a flat....and those that do, I would argue the vast majority of them don't change their own tire anyways, so it's few and far between the people that actually change their own tire. Most cars come with roadside assistance - they'll come and give you a tow to your local shop and you're all set.

You could always buy your own tire for a couple bucks - but then the other challenge - where to put it? Cars are so aerodynamic and tight, there isn't much space anywhere!