Remember also that some of you will be on a 'vacation' type of trip with the cargo area somewhat full to begin with. So, even with the space of the doughnut spare, you will probably have a very unhappy passenger with a lap full of stuff for the duration of the run to the tire repair shop.

I invest in the AAA service personally and don't care if they only cover 30 miles for a tow or whatever it is before you have to start shelling out the cash. I'd rather have the vehicle brought to a shop and have the tire properly repaired than chance a wheel/tire combo that was not really made for my car. Not to mention the loss of space in an already space limited vehicle.

Good luck with your quest guys!