Of all the specific stuff the US requires Porsche to do it's too bad that they are not one of the countries to require a spare (if Porsche doesn't supply run-flats).

I forget which countries, but there are some for which Porsche has to include a spare w/tools (all the part numbers can be found). (Middle East?)
As soon as I got my 997 I made certain I had the following (after reviewing the Porsche instructions for using their supplied can of fix-a-flat and compressor) -
1) P/N 999-571-074-30 Mounting Bolts (2) - essential for PCCB brakes, and in every case it's best to use two - these help you or a strange mechanic to line up the wheels without damaging the rotors in case the wheel needs to be removed. They are cheap - should have been available for the 996 and if you have a friend with a 996 get him some.
2) A tire repair kit like the one mentioned. - MULTIPLE CAUTIONS HERE - If you drive with a flat for ANY distance at even close to HWY speeds (US) your tire will be beyond repair so do not attempt to plug the tire or use the can of goop provided in this case. Also, if the puncture is in the sidewall of the tire you should write it off. I pumped a lot of gas and fixed a lot of flats this way in high school (long time ago) and it would be best to watch someone do this before you try it. You would hate to make a minor inconvenience a tragedy.
3) The jack and tools from a 996 or 986 - the jack is very light-weight and so are the tools. eBay!
4) For long trips take a 996 spare, there were two styles - inflated and collapsible - the inflated does not fit as well. I once finished a 1400 mile trip on a 996 spare (450 miles from Chicago to KC) as I did not have 5 days to wait for a tire.
5) Tire pressure gauge - use it weekly - it may alert you to a minor leak from a nail you may not notice otherwise. The 30 series rears can look the same with 20lbs as with 42 lbs! Even if you have PTM you should still have a good gauge in the car at all times. Inspect the tires visually before a long trip to make certain you are not 'sparking' - a term I use when you are carring a nail or screw around without leaking air. When those let go - and they always do - the sudden loss of air can quickly destroy the tire at speed. That flat you get on long trips is usually from a nail ('sparker') you left home with!
6) Some type of flashlight so you can see what you are doing at night. Of course it would also be nice to have flares, red warning triangle (like in Europe), gloves etc.
Always keep a large plastic trash bag, big enough to fit the rear tire in the car.
I had not considered the hack-saw to cut the tire off the rim. More power to you, if you can do that - you're the man!
I find that on long road trips I do not have back-seat passengers (go figure) so the 'wheel in the bag' fits fine in the back-seat. Two people would have to carry an outrageous amount of luggage to not fit the tire as well. I would certainly leave a suitcase (empty or not) at the side of the road before I would leave a tire and wheel.
I agree 100%

that the way these cars are delivered (w/o spare) they are un-reliable. I bet that by the time I can get an answer from 1-800-PORSCHE (Has anyone tried calling them?) I can have a spare mounted and be on my way - or have the tire plugged. I can live with a plugged tire for the 5 day tire delivery!